Why doesn't Sony want me to give them my money??
One Word - Activision.
Obviously, if it was up to Sony, Crash Bandicoot [and Spyro] would be already be buyable in the Vita Store and compatible with the Vita. Crash Bandicoot [and Spyro] would also be part of the Playstation All-Stars Roster as they were the face's of the Playstation 1 era, yet not on the Roster because... of Activision. People can argue this but Sony sold Crash [and Spyro] to Activision and obviously Sony can't just say, "Well, we are going to sell Crash [and Spyro] on the Vita store with compatibility in tow ok, later!"
I'm guessing here but as i mentioned in another thread but a licensing agreement must have been made with applied fees to allow Crash [and Spyro] series to be buyable on four platforms - PS3, PSP, and Playstation Certified Tablets and Phones. Nothing else was signed for the deal - which probably upset Activision that Sony Computer Entertainment Europe just threw the titles on thier Vita Store. So right now, Sony is probably is trying to sign on the fifth device - the Vita - with Activision but they are playing hardball due to Sony Europe's outing of the games before the new agreement. So Activision probably wants the fees from the possible sold games already done through the Vita Store, so while trying to sign on the new added device deal, Sony has to do damage control.
Probabability is likely but this is of course speculation as well.It could be that they are saving Crash [and Spyro] for the dry weeks when no games are coming out for the Vita...
Just an FYI:
The Crash AND Spyro games can be played on a Vita if you use an EU or JPN PSN account on your Vita.
Whatever it is that makes US different is anyone's guess.
Moreso, if you really wanted to, you can remote play the games on your us account if you have a PS3. I've been playing Crash Bandicoot 1 on my Vita just today using my US account just fine through Remote Play.