Well, most consider the Wii U a failure (though I love it), and selling more than a failure does not automatically preclude something from also being a failure.

Otherwise, it's also a handheld where higher sales are expected and only one true competitor exists (unlike the third participant among consoles). That it has only just edged out the Wii U, a console that sold historically poorly by modern standards, certainly doesn't help either.

Something can be fun and cool while also being a commercial failure, and much like the Wii U, that's pretty much what the Vita is.

It soldd less than it predecessor so its a failure? 3ds also sold less than the ds but no mention of it being a failure

Because if you score a 20 on a test, you still failed, even if the guy next to you got a 15.

Because vita is a HANDHELD, not a CONSOLE that sold for less than said CONSOLE competition. You're making it too confusing for yourself to compare apples to oranges. Vita is a failure in the context that it was outsold immensely by its competition, the 3DS, not the Wii U.

Vita is a failure in the aspect that it barely breaks 200 units a week in the US. That is abysmal for any console. Not even the Wii U does that. Wii U wouldn't have been seen as a failure if it wasn't sold at a loss. All of the top selling software on the Wii U is by Nintendo, so software is doing well enough. Hardware is where the Wii U failed in being too pricey due to a glorified bottom DS screen.

Wii U is a failure in comparison to Nintendo's past efforts and in comparison to the Xbone and PS4, Where handhelds come into that aspect is not connecting with me at all.

Because Sony is hardly mentioning it. Unlike Nintendo with the Wii U.

I like that! 

Wich device was abandoned by its own manufacturer after 2 years in the market?

By the way, you are using vgchartz numbers, that can be overtracked, since sony is not even bothered to give official numbers

2 Platforms can be a failure at the same time..

When was released the last big vita game published by Sony?

Selling slightly better than a failure does not make you a success and attach ratio means nothing when the overall number is low.