For me, it is
a. Lacking that one must-have game (like Pokemon for 3DS)
b. The main games I am interested in on PS Vita are visual novels, which I can get on PC or other platforms

It's a system I will get eventually. Right now though it has no games that I'm dying to have. However, I haven't done a lot of research on it either so I'm sure there are. But I don't have time for another system/more games with the ones I already have and ones I plan to get later. Also, money. I don't have any extra. But I will get it at some point. Probably gonna be a few years though.

I really wanted one, I still do. But as you get older and you have other interests (not just gaming) Time starts to slip form your day, and finding the time to even just play the home console becomes a difficult juggle.

Well that's just me...

I haven't bought a handheld since the GBA SP

I have vita and 3ds, for first i was regret it for owning a vita. But now i need vita because all of my gamer friends using ps party to comunicate while playing a game (xeno/mk8/destiny/mh4u/ffxiv). Why not skype or discord?? Idk...

If only we could select more than one item from the poll. I have a vita, but I only have one game on it, I would have gotten more but they all got ported to PC.

I was going to buy a Vita when I first saw Digimon Story Cyber Sleuth, but when they announced that it would come only digital I retract u.u You might think it´s stupid but I only buy physical games :P
When I read it was physical for PS4 I thought it was a joke. I mean, it´s a Vita game, the Vita deserves to have it physical...
Also, I have a 3DS :P