Love the Switch so far. 

But I'd say Wii U started with better 3rd party support. I know it died quickly, but it is slow starting up with the Switch. 

With Wii U we had:
Zombi U (exclusive)
Mass Effect 3 (a few months late, but people are freaking out over Doom which is over a year old now, and Skyrim which is 6 years old)

For a console that's only been out for 6 months its crazy good, especially when it was doomed to fail by most 3rd party developers and internet.

The 3rd party support the next year/s so far is way better then what PS4/Xbox had from 1st and 2nd party games the first 2 years.

Zombi U  (Not a good game.)
Mass Effect 3 (This series needs to be played as a trilogy or not at all.)
Assassin's Creed 3 and 4 
2 Call of Duty games that launched at the same time as other versions.
Arkham City (the definitive version IMO, but released 1 year after other versions)
Arkham Origins (Not a good game.)
Splinter Cell Blacklist
Injustice same time as other versions
Watch Dogs 

We Are Less Than Two Months Removed From the Wii U Being Nintendo's Primary Console

I think all of the positive reports coming out about Switch sales numbers and the like over the last few weeks have perhaps lead us to forget that we are only a handful of weeks removed from one of the most 3rd-party starved consoles since the otherwise excellent TurboGrafx 16 (the two actually rather remind me of one another).

One need only to look back at the reviews for the console and sales predictions from outside of Nintendo to see that pessimism largely reigned even up until launch, and it's really only been since the middle of March that people began to think the Switch might actually prove to be a sales success.

With that in mind, one can hardly expect a long list of 3rd party ports to be ready for this system from day one, and so the "test the waters" 3rd party games that currently constitute most of what has been announced should not be particularly surprising, especially given the just how poor a system the Wii U proved to be for 3rd party developers.

If the Switch continues to maintain solid sales and those first few 3rd party games sell well, you can be sure we'll start to see more 3rd party games being ported to the console.

We're Not Even at E3 Yet

It's entirely possible that we'll be seeing more announcements coming as Nintendo really tries to sell the Switch at E3 this year. Their recent Nintendo Direct seemed to support this idea in my mind, as it seemed they used it to promote everything involving the 3DS, the likely focus of E3 being instead on the Switch itself.

One can't be sure that they'll have announcements about 3rd party ports, but given there's already at least one 3rd party crossover that almost certainly exists which has yet to be announced (that Rabbids crossover that even Ubisoft seems to be having fun hinting at lately), it's entirely possible that Nintendo is really looking to wow us at E3 by saving as many reveals as possible for it. Given how evasive Bethesda and 2k had to be about whether or not their ports were a reality for a while there shows that Nintendo certainly puts NDAs to use with their 3rd party partners.

Most 3rd Party Devs Have Only Had Switch Specs for Around Three Months

Just thought I'd quickly mention this one, as it's something that came to light as reading about Snake Pass... Basically, while dev kits have been out for a while, most (if not all) 3rd party devs have only known the Switch's actual specs since around late January. If I was in charge of some massively expensive AAA game, you can bet I'd not spend the always-stretched resources on a port for a console that is not only the successor of a financial failure, but we don't even know the specs for.

That no large scale 3rd party games were ready and ported for the Switch's launch is essentially a given with this in mind.

Modern Engines Allow for Easier Scaling

It was Nuvendil in another thread who I saw point this out, but there seems to be a sense among most here that games which are graphically impressive are inevitably far more difficult to port, but that certainly doesn't have to be the case assuming they were designed competently and with scaling in mind. Lighting, Resolution, Shaders, particle effects and the like are all easily adapted to fit hardware and meet framerate goals; the real difficulties lie in the physics, AI and so forth around which the game is built and which often cannot be scaled down without harming gameplay.

The Switch is capable of managing engines like Unreal Engine 4 and Frostbite, so many (if not most) of these gorgeous AAA titles are perfectly capable of being scaled however much is necessary to get them running on the Switch if they so desire, and given the unique nature of the Switch I doubt owners would care much that the visuals won't match the stronger hardware while carrying it around in their backpack or briefcase (I certainly won't). This is not a matter of the hardware being unworkable, then, but rather is a matter of whether or not the money is there for them to make the effort.

Proving Popular With Industry Leaders and Devs

This one is of uncertain benefit, but I have to think it can't hurt that people from Bethesda's Todd Howard to the Dark Souls team expressing a seemingly sincere affinity for the console. It really seems like they're primarily waiting for sales numbers to show that the money is there.

Very Easy to Port Games To

This is probably the biggest improvement from the Wii U... games are proving remarkably easy to port over to the Switch, especially when compared to all past Nintendo consoles.

The best example of this so far would have to be Snake Pass, which apparently was able to provide a port for the Switch that runs great less than two months after receiving the official specs of the hardware itself. The videos about Snake Pass from Digital Foundry are actually quite informative of how much easier Nintendo has made the porting process, and might be worth a watch for ya :)

https://youtu.be/kX7Rn9YUXm8
https://youtu.be/-wBvsx84Dys

The Switch Has a Strong First Party Lineup

Between the remastered ports, the relative unpopularity of the Wii U (which has allowed for BotW to be quite a system seller), and the notion of playing these games while out and about in portable mode, the first party lineup this year is looking quite strong and the hype surrounding them is real. Even ARMS, a rather simplistic looking game at first, is beginning to excite an increasing number of people, and I know I personally am looking forward to almost every release this year. Even should there be no surprises at E3 (which seems a bit unlikely), the lineup culminating in Odyssey this holiday season is certainly superior to what the Wii U had to work with.

This is important as it will continue to provide additional motivation for people to buy this console throughout the inevitable 3rd party drought as this console attempts to find its legs. This leads to the last big reason to remain patient.

The Switch May Prove More Popular Than Expected

The Switch has certainly had a much stronger launch than most predicted or hoped for, but whether or not it will have legs and continue to sell over the coming year has yet to be determined.

The key thing to consider, though, is something that should be obvious to everyone and yet apparently it isn't: if the Switch continues to sell well and the money is there, 3rd party ports WILL come.

It doesn't matter what the platform is (the Wii being a great example), if devs feel there's money to be made by porting their games to a console that appears to be a success, they'll find a way to provide said ports. Given the pessimistic initial projections for the Switch and the failure of the Wii U, said devs had absolutely no reason to think they'd be making any money they spent on a Switch port back until quite recently, and even now we're still likely in a "wait and see" situation for a couple more months before you'll start seeing people buy in (if it continues to sell well) or pass it up (if sales drop off).

This is why the decently strong 1st party lineup over the coming months full of games that are both highly anticipated and often are superb multiplayer options are so important, as if they can continue to draw solid enough sales that there's a healthy, large base of potential consumers aching for some portable 3rd party games by the start of next year you will certainly see those ports begin making their way over.

 To be frank games like Mario+Rabbids and Octopath are more interesting third party exclusives than Zombi U