This show is unwatchable as an adult

I really want to like the Munsters but as an adult, it's just unwatchable.

The tone of show makes it play as if it's designed for kids.

I.e. Every time Grandpa says magic words, they sound like a nursery rhyme from Sesame Street. But that's just one example. Everything about the show has that exact same babyish tone to it.

Yet despite the show's overall extremely babyish tone, sometimes it also features themes that are totally inappropriate for kids. For example, one episode has Commissioner Gordon guest starring as the lover of a Black Widow woman who murders people.

Another example is when Grandpa transforms into a woman who pretends to be Herman's lover. That was one of the most creepy things I've ever seen!

Why does the show have adult themes if it's a kids' show?

Why does the show play like Sesame Street 98% of the time if it's an adults' show?

How do you enjoy this show as an adult despite the fact that 98% of it plays like Sesame Street?

I have no idea why this show is popular. It's aggravating to watch. What's good about it?