We spend a lot of our time here reassuring each other that there's nothing wrong with crossdressing, that there are lots of common reasons why we do it, that "normal" doesnt mean much and everybody has their kinks etc etc ... so its easy to forget that there is that small minority of us who really are just plain nuts. We've probably all run into them online at one time or another, too.
I think the same is true of any group of "eccentric" people with unusual pastimes. Probably 98% of Trekkies are normal, if geeky... but there's that 2% you wouldn't want to be locked in a closet with. I'm sure there are reasons why these people are the way they are, but we have no hope of understanding them after just one or two casual encounters. All we can do is tolerate them, and we can only do that up to certain limits. I think you handled this just right.
About "representing us"... this is an old argument that doesn't wash anywhere. Judging a whole group of people by one or two bad experiences is prejudice, by definition. (If many-most of us were like that, that would be a different matter). Its not anything related to CDing or TGism either. You don't have to look far to find men who are pigs or women who are gold-diggers, but if anybody suggested that made it ok to label all people of either sex that way, we'd roast them - and we wouldn't even bother discussing whether that was a reasonable viewpoint. I don't see this is any different.