I have no problem with their games honestly. Nintendo have always made good games. Some interest me some don't. I just hate them as a creator of hardware, and for some of their acts towards their fanbase.
Honestly, I've had a problem with them since the Wii, though I chalked it up to it just being aimed at a different market. I couldn't play the Wii for more than half an hour before my wrists started aching incessantly.
I bought a Wii-U because literally everyone on earth was saying it was the best system of all time, but I bought it and only 3 games interested me really. This isn't Nintendo's fault, I'm not really their demographic. The games I've liked of theirs in the past were usually made by rare, or a Zelda or Metroid title, none of which I've gotten on this console.
Some more Atlus games would be nice too. On 3DS I'm loving Etrian Oddyssey, SMT, Fire Emblem, and the like, but there doesn't appear to be much like that on the Wii-U which saddens me.
All that is for naught though. They have barely any idea how the internet works, their systems are unintuitive (especially with options and the like) and downloading things on the 3ds store is annoying as hell since I have no idea how much download it's using or how long it's going to take. I have a lot of little niggles, but they all add up.