Haha, I'm going to RTX. I hope I don't see any meme shirts, unless they're RT related. ._. When I'm out eating or something, It bothers me, It's like, wow, great, that started on 4chan, most likely on /b/, a place where the little high school douchebag wearing that shirt would freak out in the first five minutes of seeing. -,-
I hate to break it to you... ...some of us enjoy that kind of thing. You see, a convention is a place where you get to flaunt your love / enjoyment of something. And since RTX is an internet media heavy convention, you're going to be exposed to many internet inspired things. You have to be like the squid in the ocean, son: just ride the tide and go with the flow.
If people make their own stuff, I'm totally cool with it, but a bunch of dudes in a suit deciding to release x amount of shirts for x price and all that pisses me off. :| And then when I see it on the kid who's name on facebook is $w@g Bo1i, it hurts me right in the nostalgia, from seeing those memes gain popularity.