I mean technically, Sony could release a digital game on the Vita, larger than 4GB to bypass this limitation, but why would they cap the game cards so low with technology so advanced in this field?
Sony has always pulled this bullsh!t. Look at the first few years of the PS3. Why did most of the games seem like a very minor step up from the PS2 and mostly suck...because sony limited the developers to how much prosessing power they could use.
The reasoning is to make a real contrast between launch games for the system and late games in the system.