Does anyone want to see people drunk? I doubt it. But a person drinks because they want to drink not because a shirt they are wearing. They may drink while wearing the shirt but the shirt isn't
making them drink. If I wore a drinking shirt and yet had nothing to drink that day you'd be incorrectly assuming something about me.
Your point about Disney I agree with and was more or less my viewpoint. If you removed the shirts and yet still saw someone exhibiting annoying drunken sloppy behavior you wouldn't attribute that to a shirt. Disney has alcohol on both coasts. You (general you) would still have issues with that aspect unless you removed all traces of alcohol available and never let anyone in who you suspected even had the hint of pregaming (which I kinda assume they do at least look out for that).
I actually think it's equally trashy (to use your terminology) on Bourbon Street. It's so predictable, so overused IMO there, etc. Not that I don't understand what you're saying. But I don't think it's the shirts actually making the people trashy

If people want to wear them it's no biggie to me though I think some are eye-rolling worthy/overplayed. I guess I don't take the shirts to heart to mean something and I mean all the shirts like I mentioned previously.