@Blahman11
because you need a full port to play a ps2 game on the vita, its not as simple as just emulate the ps2 on it. the ps3 could emulate the ps2 to some degree when it was allowed to, but even then it only emulated it at sub hd levels, and the vita if i remember right uses a modified arm architecture opposed to whatever the ps2 used, which would demand at least 7X the processing power of the ps2 to even start to emulate.