How come the original Xbox had no RPG games and the Xbox 360 now has a bunch of RPG games?

I microsoft trying to steal away Sony customers. Xbox now even has games like Final fantasy tactics. The original Xbox just had Fable, which was the closest thing to an RPG, but now the Xbox 360 has turn based RPG’s.
I didn’t like the original Xbox for that reason, by now that the Xbox 360 has a bunch of good once, but the PS3 has none, I become an Xbox 360 fan.