I don't really see it this way. I bought a Wii U on the cheap 12 months after launch knowing full well the system was likely going to remain a niche product for most of its life. Across the three years I've had one I've bought 26 retail games (most of them exclusive), 10 Virtual Console games and 14 indie games, plus several DLC packs for several games. I've had hundreds of hours of multiplayer fun, hundreds of hours with some great single player games (though not as many lengthy, ambitious games as I would like), fantastic platform games (one of my favourite genres), and a number of surprise gems I never saw coming when I bought the system, things like Splatoon, Captain Toad, Hyrule Warriors, Affordable Space Adventures, Tokyo Mirage Sessions.
Would I be annoyed if Splatoon, Kart 8, Smash were remastered for Switch? No. Three of the best Nintendo titles of recent years have been confined to an unsuccessful platform. They've sold brilliantly considering, but the more people that get to play those games, and the more life those games get, the better.
Do I feel betrayed by Nintendo? No. Maybe I'd feel differently had I bought a Wii U at launch, but the simple truth is--and it's something some people on these boards have struggled to accept--it does not make sense for a platform holder to continually throw money at a non-viable platform. Nintendo said in 2014 (I think) that Wii U needed to sell 5 million units a year, at least, to be a viable platform, and if it didn't achieve that threshold, they would have to move on. On top of that, the longer Nintendo burnt cash trying to turn Wii U around, the smaller the chances of Switch succeeding. Nintendo have finite resources, and personally, because I want them to remain a platform holder, I think it's a better use of their time and resources to push Switch strongly from day one than it is for them to keep throwing money at a system that has already failed.