I'm not going to wade in on the Wii U aspect here as some are trying to.
But on the Vita front, it's quite simply a product that's market migrated before release. A big selling point of the PSP was the media functionality (MP3s, UMDs etc.) now people can do all that on their phone (and better if you have a high end phone with 1080p display etc.)
They were never going to buy a Vita. The other piece of the puzzle isn't so much the games, it had pretty much everything everyone says the system should be getting now in the first 12 months to have been a big success if that was the problem.
It's just quite simply a case of the market for a dedicated handheld is dwinding rapidly and Nintendo fans are generally more keen on the idea still. Though as we saw from 2011, even they took an awful lot more persuading this time around than anyone anticipated.