When people say something to me like "that's not right," I usually take it as an opportunity to get a free lesson. It doesn't hurt to learn more, even if it's just someone's opinion.

My guess is the guy who "put you in your place" was trying to impart information and not make you stop playing. He might not have given any thought to how you'd interpret what he said. Everybody has to start playing somewhere - it's part of the learning process. If in doubt, ask him. If he says he doesn't want to hear you play, smile and give him some ear plugs. If it's a problem for one person in an entire group, let it be HIS problem.