I mean... I can see why rebels didn't pilot stolen TIEs without going into doctrinal differences. Standard TIEs have no hyperdrive; you follow a TIE, you find a carrier or a base. You can't follow an X-wing that jumps to hyperspace and the Alliance can't risk their bases being flushed out easily.
@Leucrotta Rebel pilots are a scarcer commodity too! It takes a lot of courage to decide 'I'm going to fight against the Empire that owns basically all the stars.'