The thing is, people hold third party titles on Nintendo platforms to the same standard that they hold first party games, and I think that developers fear that for sales reasons and critical reception. Obviously, they're performing against a so tired company that has made many great titles, and I think that people frown on games that don't offer the same level of polish. It's why Wayforward games sell well on Nintendo devices- despite the overall quality, they out out material that's polished from many aspects and have been accepted by fans in that sense.
I know the games I wanted to play the most on Nintendo consoles were titles that seemed comparable to Nintendo titles- Bayonetta, No More Heroes, Sonic Colors, Fluidity- things that you didn't feel like you could get on other consoles. Of course, some of those games are found elsewhere an garner cult followings, but I see Nintendo platforms as "cult" platforms more than any other. Especially considering their core fanbase is pretty much a cult itself. If you're like me, you look for what is different and appealing in a console rather than what's the same. Unfortunately, that mindset isn't profitable and it's clearly not what people what judging by the opinions I've seen here and elsewhere.