This is an active choice of such marketplaces. They could choose to be more strict if they wanted to. Yes they'd probably have a moderately hard time getting ri

This is an active choice of such marketplaces. They could choose to be more strict if they wanted to. Yes they'd probably have a moderately hard time getting rid of all the existing spam, but once they start banning vendors and raising verification requirements, the volume decreases. I'm permanently banned from publishing on the Google Play Store because the name of my app was too similar to another. So they do have the ability to enforce things strictly when they want to.