Though, please don't desecrate this manga just because it doesn't kill the bully. It is someone else's story and he can write it however he seems fit.
Although I agreed with you for the rest of your post, you missed the point here. I'm pretty sure the person you were responding to wasn't complaining about that one situation on its own, but rather about how (almost) all stories try to take a "moral high ground" and have the protagonists forgive regardless of whether it suits their character or not.