The PS Vita is a complete and utter failure. It's sold worse than the Wii U.
Also, Sony doesn't make first-party games. Nintendo does. Nintendo's main appeal is on the backs of their first party efforts. It's stupid for them to have two platforms because they are splitting their resources and competing with themselves. If Nintendo only had one platform to concentrate all their efforts on, then they would be in a stronger position because anyone who wants Nintendo games would be forced into that one platform and they wouldn't have to decide between two Nintendo options. I don't understand how this basic logic is wrong. You did nothing to disprove it. You just said the Wii U is bad because X Y Z reasons. My summary of Nintendo's situation and your reasons for Wii U's struggling can both be true at the same time.
As for Nintendo becoming a pariah developer, people have been saying this since the 16-bit days. You don't have to like Nintendo, but you also don't need to over-dramatize things like this. Look at the recent success of the NES Classic. There is a lot of love for Nintendo out there - they just need to tap into it with the right product. To say that the entire mainstream gaming community will suddenly hate Nintendo's brand name is very weak, non-persuasive rhetoric, and pure emotional nonsense.