If you don't know one of the higher profile features of the Nvidia Tegra Shield line of products is the ability to stream from your PC to your Shield device in home which allows you to effectively play your PC games on your TV easily or on the Shield tablet. You can see here the tech in action being streamed to a Shield tablet:

Now of course, why should Nintendo allow, this, they wouldn't be making money, right? Well what they could do is simply have a PC Nintendo Account app. You get the PC game, pay a $8-$10 licensing fee towards Nintendo and the Nintendo Account could make the game "stream ready" for Switch (with Switch specific menu options/Joycon support, etc.). So there you go, Nintendo gets their standard 3rd party licensing fee cut for doing basically nothing. 

Nintendo could also regulate which games are available this way so that's there's not too many that they drown out the regular Switch titles. Of course this would have to be a home only proposition (unless you're streaming from a laptop), but still it wouldn't be the worst way to maybe offer some games on the Switch that would never be available otherwise most likey (ie: GTA VI, Anthem, Destiny 2, Witcher 3, Street Fighter V ... hah) for those who have a Switch and don't want to purchase a PS/XB just for like 4-5 franchises. 

Idk... I'd be worried about a negative affect on 3rd party multi-plats. A license could maybe help on Nintendo's side but still could have a bad affect 3rd party wise.

I've always wondered why this wasn't done. I remember some company (not Nvidia) edit: Actually I think I found the company 'Rainway', was planning on bringing over a service and said they would try to put it in the eShop that did something like this but so far no sign of it. 

http://www.nintendolife.com/news/2017/06/pc_game_streaming_service_rainway_confirms_switch_as_a_supported_platform

http://comicbook.com/gaming/2017/05/19/pc-game-streaming-app-still-coming-to-nintendo-switch/

Guarantee 100% this was at least mentioned between some higher ups at both Nvidia and Nintendo at least as a side mention. Maybe they are waiting for the hopefully inevitable drop of applications like Netflix, Youtube, etc. to release something outside of just games.

I think Nvidia would gladly have them allowed to offer the service. Since for every Switch that is sold, Nvidia makes money on the chip (Tegra X1) that powers it.

This could be an emergency option if 3rd party support stays low in the future. By this way they could still offer 3rd party support to attract more customers.

Yeah I agree, it's not a perfect option, but it's better than having no fall back plan at all. 

Pay Nintendo money to turn Switch into a WiiU tablet for PC?

Pay a small fee to be able to enjoy PC games on your TV/Switch around the house with Nintendo controller support. Most people don't have their PC in their living room and most PC games are like $10 less anyway. 

Given that NS is their only future platform, Nintendo will have mutiple backup plans ready to avoid any Wii U-Style failure. I would bet this is one of them.

To Nintendo's credit, the WiiU tablet is the best streaming device I've used but for any PC-Switch connection it would have to use wifi like everything else. Steam already offers this over wifi don't they? I'd rather use a cheap tablet and not pay an extra $10/game.

Steam offers it as more a remote streaming service but differs as you either need another PC that has the program installed (think using a HP laptop to play games that is on your $2k Deskop) or using  Steam dedicated consoles (that hasn't sold well)

You cannot use Steam to play on a tablet unlike Gamestream (Nvidia's streaming) that can play on tablet devices.