It’s not the ugly, it’s the crazy. You get a large quantity of people that are slightly abnormal and put them in a situation where they have no reason to “blend” with normal. Lots of people running around in costume, even the non-costumed ones will be having these oddball conversations. You’ll be out of the normal world where the important things of the world are inflation and the war on terror and into the fen world where important things are Kirk vs Pickard and whether “the trilogy” is Star Wars or LOTR. It’s an alternate reality, kind of like a college football game only it lasts longer and has less structure.
That sounds attractive! Anything to get away from the real world, at the moment.