I think it's a software issue. The main reason pirating is so big on PC is because there's no reasonable way for a normal person to buy all the the good games coming out. The PS3 is more oriented towards a few superstar titles releasing every year.
Result: Paying 200$ to get your PS3 hacked isn't worth it to get 5 good games free.
Paying 200$ to get your 360 hacked is worth it to get 10-15 good games free.
Wii has more 20 million sellers than PS3 has 5 million sellers.
Acolyte of Disruption