Sorry you had to go through this, I don't blame you for being upset, I would be too. I ride different disciplines (including my 25 year old GT) and yes, there can be a bit of snobbery on both sides but usually not played out like this, at least where Im from.

Try not to let those people bother you. They probably have to try to prove something to themselves to make themselves feel superior. Your bike is heavier and tougher to ride than theirs so you're already ahead, so to speak, because you have to work harder. Don't let them ruin your weekend. They aren't worth it.