I gotta ask: who the Hell watches these Purge movies?

They’re on their third one by now; and I get that they’re ridiculously successful. But as near as I can tell the underlying premise is simultaneously highly offensive, and even more highly absurd. Who, exactly watches it?

I am ready to accept that there’s something of value about these films that I’m just not seeing.  Not everybody likes the stuff that I like, after all. But I have difficulty getting my head around the appeal.