The NS needs Japanese support not western support.

So it can sell like shit in the rest of the world but do alright in Japan like the PS Vita? Because that's exactly what happened with that system when it had no western support but had japanese support. And I say alright loosely there, because it still sold horribly, just not as horribly in Japan as the rest of the world.

The NS needs all the support it can get. Nintendo isn't in a position to be picky about which third party developers they want, they need to be trying to get as many as possible. The NS is already going to be a huge success in Japan and Nintendo have always had better Japanese support than Western support, so if anything it would be that they need to improve western support instead. 

Nintendo Switch is at a very early stage. Gearbox won't be the only developer who is afraid of developing for it now.

YAY! I hate their games!

Not true.
It had a lot bugs and framerate problems during launch but now after all the patches it is very enjoyable imo.

If a third party says they don't want to make any games for Nintendo, then Nintendo shouldn't have the mindset of "Oh fuck those people then, they aren't even important to us, we don't need them" and start burning bridges or anything, they are not in a position to be doing that when they have already had troubled relationships with third parties for years now, they should work to reach an agreement or an understanding with those developers to change that.

I'm not saying Nintendo should give in to third party demands or anything, it's Nintendo's system they can do whatever the fuck they want, but if they want to keep third party support they should at least attempt to reach an agreement. Of course they need to please potential customers as well, but part of that is making sure that they will actually keep consistent third party support with this next console so that those customers that wanna buy a Nintendo console but usually wouldn't because it misses a majority of third party games, can finally have no excuse not to anymore.

Unless you're one of those people that buys a Nintendo console not expecting a lot of third party support and mainly just to get Nintendo games, since I know a lot of people do that, then it wouldn't matter to your purchasing decision anyway. There's never any harm in offering more games on your system, which also adds in to the whole "pleasing potential customers" thing. 

Borderlands was one of the best and most successful new franchises of last gen. Anyone discounting that is being ignorant or petulant. It would be a big deal if Nintendo got that.

Of course, Borderlands 3 is years away so they have no reason to rush to a judgement over the Switch. If it's popular and feasible, they might consider it.

This also brings up the interesting case of Gearbox allowing Sony to port Borderlands to the Vita. Sony paid for another developer to port that over. Would that kind of thing be in play if Nintendo is finally serious about third-party support?

I remember it was running below 20 fps everytime but it was 2 years ago

This whole thing seems pretty pointless since what you're saying can be answered with one thing: The Nintendo Switch is not a "dumbed down PC". Just because a developer maybe wanted that doesn't mean Nintendo can snap their fingers and magically change it to that for them. That developer has to deal with it.

So if a developer was hoping that Nintendo's next system would be more like a PS4 or Xbox One, and might not want to support it because of that, its up to Nintendo to work with that developer to come to an agreement and show why the Switch is still worth supporting, not to have a mindset of "Oh, you didn't like it? Well we didn't need you anyway" or some shit like that. At that point they would just be burning bridges since, as I said already, they already have had troubled relationships with third party developers for years now. 

Nintendo isn't going to lose consumers by trying to offer more games on their system. I have no idea how you're jumping to that conclusion or think that offering more games on your system can ever be harmful, but you're entitled to think whatever you want. 

Also I feel like you should speak for yourself in saying that consumers don't want a Nintendo console that is a dumbed down PC, because i've seen a lot of people that were very vocal in wanting Nintendo to just make a regular console and not have any gimmicks or anything special and just wanted it to be a box and controller. I personally don't agree with that because I feel like Nintendo's constant innovation in every generation is what the industry needs and what sets them apart and makes them unique from everyone else.

Fair enough. We don't even know how the console is going to do, so being cautious about supporting it fair enough. It's still up to Ninten to make this thing a success.