Goku really doesn't use any other attacks when he is ssj,ssj2 and ssj3 but i do undeerstand why the took the sprit bomb attack of the list when he hits ssj, he can still use it he just never does, why he not be able to use in the first place. Off the record i would just like to say when he was fighting pikkon in the other world he went ssj and fought with pikkon and then called out Super Kaioken.