Because they enforce when someone complains. They aren't going to proactively ban stuff unless they really have to (e.g. something that is very obviously illega

Because they enforce when someone complains. They aren't going to proactively ban stuff unless they really have to (e.g. something that is very obviously illegal/scam/etc.) So if nobody complained about the other apps, they didn't get banned. It is that easy. That someone else does something that violates those policies/laws too doesn't mean that you get a free pass, unfortunately.