Congratulations your assessment of the situation is probably fairly astute. Adopting the platform so early was likely a mistake on your part, but if you feel there is no future in the platform. Then the best coarse of action is to cut your losses, and transition to something that can actually service your needs. Nintendo promised a change for the better as far as core gaming was concerned, and it obviously hasn't materialized, and the weak sales will probably see to that continuing moving forward.
I wouldn't let the boasts about Nintendo first party games bother you too much either. Most of the people who say those things actually own another console. Which is actually their primary console. They wouldn't after all deprive themselves of games like the Elder Scrolls, Grand Theft Auto, Tomb Raider, Bioshock, Dead Island, Borderlands, and any number of great third party titles. Which didn't come to Nintendo last generation, and probably wont come to Nintendo in this current generation.
What it really boils down to is they really want you to support their multiple platform lifestyle. They don't necessarily care if you cannot afford that lifestyle yourself, or that you have to sit around paying their dues for them. After all when Zelda or Mario aren't coming out they are playing fantastic games on their 360s or their PS3s. They really couldn't give a rats ass if you aren't getting the best gaming experience possible.
They own a Wii U for all of a few games, and if they were locked in on just that console. You can bet your ass that they would be doing what you are doing right now. They wouldn't put up with not having games to play, and not getting to play the really awesome third party games. So why should you have to put up with it.
I am sorry but Zelda isn't a substitute for The Elder Scrolls. Mario Kart isn't a substitute for Grand Theft Auto. A Mario platforming game isn't a substitute. For all the great shooters/action/racing games. I am not saying the games that Nintendo makes are bad. Just that they aren't worth missing out on the bigger world of gaming. No gamer can last long on all of three great games a year. Most hardcore gamers expect to be playing six or more.
You made the right choice. If they want those Nintendo games so bad. Then they need to make the Wii U their primary platform, and buy games accordingly.