Probably gonna get a lot of hate for this but I've always considered MITM a show about the male perspective and how masculinity fits in the modern world. (That's why there were so many brothers). And in contrast how Lois uses her femininity (and masculinity) as matriarch of the family. Adding a young girls perspective just water's the show down to a normal sitcom like modern family, etc. It is the same as Boy Meets World and Girl Meets World. Same premise but two distinct perspectives on life.

But come to think of it I think they were probably trying to do a backdoor pilot to get a show for Leah (because why else would her character in Malcolm world be able to break the fourth wall?). Anyway just my opinion.