A lot of it is down to licensing concerns. While Disney has (or had, it seems to be up in the air at the moment) what is essentially a permanent a rolling copyright on their property thanks to lobbying congress and the senate the other studios have to work within the existing laws which means they have a limited amount of time to use the franchise in order to keep the license. That's why you see a constant flow of reboots, prequels and sequels. So in order to maximise their profits they aim for demographics that would also buy the merchandise for that IP.
