1/ Pretty Rhythm is related to Pretty Cure.
It isn’t. They have different companies, different backgrounds. They have nothing in common besides the fact that there’s “Pretty” in their names.
2/ Pretty Rhythm is a magical girl show!
It’s not. It’s a sports show with girls as the protagonists. As such, it has a lot of romance going around in it.
3/ Pretty Rhythm is an idol show!
It’s not. Like I just said it’s a sports show, with friendship, love, rivals and tournaments. I’m really not into idol shows. The exception being Aikatsu!
I didn’t/don’t watch Idolm@ster (though I like Azusa), AKB0048, Love Live, K-on! etc
4/ Pretty Rhythm is about cute girls doing cute things with cute clothes with lots of fanservice.
False. It’s not just cute girls doing cute things. Even if you don’t like idols or cute things and cute clothes, it’s possible you’ll like it. In fact, I hate cute girls doing cute things. See above. And there’s no sexual fanservice.
5/ It’s target audience is kids so it must be simple and boring
It may be targeted to kids, but it’s story, characters, especially the parents are one of the best I’ve seen.