It's only rude if the person you're saying it to takes offense. And I mean really dude, you handled this pretty poorly.
http://i.imgur.com/6yIcqSk.png
http://i.imgur.com/fcn4qDI.png
http://i.imgur.com/yXpJ3Zo.png
If you're going to have that kind of discourse with a regular user at least do it in a PM. I find the way you acted more out of line than what was actually said.