I’m confused why you’re confused? Their position is just don’t vet the games. That’s what they’re saying. It doesn’t presume some “magical way to tell the difference”. You just don’t check the games.

Now, this part is just my interpretation, but I believe they’re operating on a “caveat emptor” methodology. They shouldn’t let malware through obviously, but they might believe it’s on the purchaser to not buy games that look like slop.