No, you don't have to wear a tux. If you don't own one, for most people the extra cost of renting one is pretty silly. And don't worry about it either. No one will really care.
If we're not having fun, then why are we doing it?
These are DISCUSSION boards, not mutual admiration boards. Discussion only occurs when we are willing to hear what others are thinking, regardless of whether it is alignment to our own thoughts.