Perry Home Counting Royalties While Jon,Neal,Ross Tour,Why??

i've heard all the stories how perry is able to sit at home counting his royalties coming in but i've always wondered something.if steve is so well off why aren't the other three members who have been in the band for decades also able to do this instead of having to slave to the grind touring year after year.i read somewhere in the herbert interview that steve made them sign something and that changed things drastic to perry's favor and i wonder what year this happened and what exactly did the band members sign over or agree to that changed things so much? is this the main reason or are there other factors to as to why its this way.