It's completely useless for intro courses. But in my experience, intro courses are completely bimodal for CS: some students just get it and some just don't.

Sure the later can copy their assignments. But once they'll hit a non-trivial assignment or a code review in a more advance class they won't be able to fake it anymore. You are just delaying their transfer to another major. And that gives the CS department one extra course they can collect tuition from and justify hiring TAs for...