[Certain]

So then what's the point of feedback at all?

If I notice a writer consistently not taking my advice, I generally start to stay away from their work entirely. There's no reason to not be constructive in your criticism. Saying "This was dope" and leaving it at that at least makes the writer feel good for a quick second, in theory. Calling a verse wack and leaving it at that does nothing, unless you've got well-established credentials and the respect of the writer.