The clarification should be added to the OP, btw.
Vita has better third party support than 3DS? are you serious?
Even Yoshida acknowledges that it has been difficult for them to attract third party publishers.
Yoshida's talking about worlwide, which is true, no one in the west cares about making handheld games and that's what their PSP/Vita "strategy" consisted of. Making portable console-like experiences.
He's probably talking about quantity. There's quite a Japanese 3rd party for PSV but most of the quality 3rd party are on 3DS.
Nah, it's just your opinion. I think the 3ds' library can't hold a candle to the Vita's, honestly. But, hey, it's my opinion, it's not facts.
Vita's 3rd party support is rather "anime girl face". It's no wonder people into visual novels and very minor JRPGs like it, but to say Vita is a healthy platform is a stretch.
It's not successful in the way that Sony wants to but it is healthy for western publishers.
If it wasn't healthy we wouldn't see so many localizations, they're clearly making a profit.
If you check the amount of games the PSP got from publishers like NISA or Aksys in like, what, 10 years, you'd see that the Vita so far has got around the same or even more games in just 3.