Ok, I understand your frustration based on your post.
However, I believe that while the fans were naive about the rule (I was), the special teams players must have known the rules. After all, it's what some of them do for a living, and they have a dedicated special teams coach.
Looking back on it, I don't recall ever seeing a punter getting pancaked on a block. Part of it might have been that they're usually the last line of defense. But they never seem to be blocked and are left alone for a one/one tackle attempt on the ball carrier.