In 2016, lead actor Melissa Joan Hart told HuffPost, "Yeah, season by season our show's cast would come and go based on audience reaction, and sometimes there'd be dispute about contracts and negotiations as far as payment goes for certain actors. And just bringing in a fresh perspective from a different character.
Also, there's a lot of politics that go on behind the scenes, like when a writer develops a certain character they get paid on the [likeness] of that character for every episode. If a writer develops a character, but that writer's gone, and there's bad blood, they might get rid of the character they developed, so they didn't have to pay them anymore. There are a lot of things that go into that situation."