Here's a question I have. 

Let's say the Switch has a good year. The PS4's first year sold about 18 million consoles. Let's say the Switch sells well, even if not at that level: 9 million units for example.

Fill in a different number if you need to. Jut assume the number is considered a strong, viable number. 

The sales are there, but most of the top selling games are 1st party, as is custom these days. Breath of the Wild sells 5 million units, Mario 4 million, Splatoon 2 million, Fire Emblem Warriors 1 million, Arms 1 million, etc etc. The numbers in this situation aren't important beyond them being 'good'.

However the third party games, while selling, none of them are doing better than the first party titles. In a sales list for the games it would be something like this for the million plus titles

Breath of the Wild > Mario > Splatoon > 1/2 Switch> Mario Kart > Arms > Warriors > Bomberman > Dragon Quest > FIFA

Will this cause problems? Assume that many first party titles, even if they aren't past a million yet, could pass it within a years time. They would not take years to limp over to it like ZombiU

There is no reason for third parties to port their big new AAA titles, with a few exceptions of course.

Cost of developing a port < < < < < < cost of developing a full game. So yea they still make profit

Its part of the reason nintendo doesnt get much 3rd party support so yes.

The typical reason is most buy a nintendo console as a 2nd console, only to play nintendo 1st party.

They buy multiplats on the other systems (they run better, higher resolution, maybe cheaper too ect).

3rd party notice they dont sell much on nintendo systems and go "why did we spent time&effort&money porting this thing?"

So yes, its a problem.

Sadly when your hardware is considerably weaker than competitors, you cant expect to get the same versions (fps,resolution ect).

So the circle will continue. People will buy 3rd party on Playstation 4 or Xbox One instead, and again just the 1st party nitnendo games on the switch.

which will lead to nintendo getting much less 3rd party for the switch.

The exception is if nintendo sells a bazillion million units of hardware.

However nintendo choose to be greedy with launch prices... so its not going to just magically sell insanely well out the gate, which will delay when 3rd party will want to jump in ect.

It would depend of the kind of 3rd party game. Small japanese devs and indies who make A-AA don't really need that many sales to make a decent profit. The Switch is, in theory, easy to port things to, so it should not be that hard to port things to. AAA games are a bit tricky, because most of them are going to need a downgrade to work, specially if the Switch is not the main console to work on.

3rd party support for Switch will primarily consist of small-medium sized Japanese, indie & kid/family software so the likelihood of 3rd party support sticking around on Switch is highly probable since this is the type of 3rd party software that typically does well on Nintendo platforms and don't require massive sales to be profitable.

It's pretty simple. They need to make at least as much money off of their Switch games, as they would expect to expect investing that same money into games on other platforms. It's all about that return on investment.

Install base doesn't really matter if the profitability is there.

Third-party publishers and developers don't care if flagship first-party games out-sell their own offerings. That's a rationalization made up by some Nintendo fans to soothe their own bruised egos.

What third party publishers and developers care about is the return on their investment and the long-term viability of a platform to demonstrate market growth.

I think they're fine with Zelda or Mario doing big numbers. Those games are system-sellers, which help expand the user-base. However, they're also looking at a limited attach-rate. Zelda/Mario at the top is fine but when the rest is rounded out with Mario Party or Star Fox, then there is a problem with the market either being bound to the "Nintendo" brand or pre-disposed to a certain aesthetic that does not favor most third-party franchises.

If that's the case, then it would require a lot of money and effort to re-position the market. It would require co-operation from Nintendo and all the major third-party publishers and even then it still might not be worth the investment.

The just need to cover the porting costs and make a profit. The switch could sell 2 million units but if all 2 million people bought Skyrim and the port made its money back at 1 million we'd probably see another Bethesda game

This is all that needs to be said really.

If the game sells enough to where the cost of the port was worth it and they made a profit, they'll continue releasing games on it.

So basically if the Switch has the userbase big enough and people actually buy the third party games on their Switch then third parties will keep on supporting it.