a) It required giving them my email or creating an account or some crap. That's an absolute deal breaker. I know they had some weird thing where it could generate an anonymous id or something, but it's not sufficient for me. I must be able to use the app with no further communication to the producer of the app.

b) I like using iTunes for Podcast discovery, and having a separate app makes that harder.

Also, looking at the website for Overcast now, it has social features like sharing podcasts on Twitter. WTF? I just want to listen to some shows I like. I don't want to give or share anything with anyone!