This shouldn't apply to ring at all, cause you're not trying to eliminate someone.

But in a tourney, personally it pisses me off when someone tries to bet me out of a pot (bluffing with nothing!!!) when the only reason I called was to give the short-stack even worse odds of surviving. The only time you should bet is if you think you have the short-stack beat for sure. (Checking down with the nuts is pretty silly) I don't think it's about manners, it's just about being a fucking idiot and not understanding the basics of tournament poker.