Lost Its Magic

One of the terrible things about media aging is that it can lose what made it so lovable, leaving it as a hull of its former self, existing for almost no reason other than its creator trying to Beat Every Dime Out Of It. Unfortunately, most times if this happens, it's not going to have its magic restored. As an effect, it'll become a Zombie Franchise.

This is very common with reboots. See The Reboot Curse for more info on this.