People that are horders or smell bad along with other issues are likely suffering and deserve some empathy.
This is true but it's worth noting that "Cat Piss Men" specifically are the result of a very specific issue which is not necessarily directly connected to mental health issues, nor learning disabilities or neurodiversity.
I found this out when I once, for an afternoon, became Cat Piss Man. It was horrifying.
Turns out that odour has a specific, replicable source - if you leave clothes damp, and then say, put them in a suitcase (and it's not in a super-dry environment so they don't somehow instantly dry in there), and they get a bit "mildew-y" smelling - which isn't the strong catpiss smell, it's just that faint "uh-oh" odour - and then you let them dry, and then you put them on and start walking around, and maybe it's warm so you sweat (and I'm not talking sweat heavily, just like, at all), then you too can become Cat Piss Man with the unique and utterly devastating odour.
Most embarrassing thing - I was literally on the way to the gaming store (Orcs Nest to be precise) when I realized I was the source of that smell - so I was very nearly Cat Piss Man in a gaming store. Like, minutes away.
And I guess the reason this happens at gaming conventions is that a lot of people going aren't used to doing their clothes-washing properly (sometimes because their mum does it, let's be real), so they wash their clothes, and before they're dry, they shove in the suitcase, and it's off to GenCon or w/e, and then they arrive, and their clothes smell like that, and apparently they just decide to wear them anyway, rather than miss any convention time going out to find some non-stinky clothes, because they're too excited to be there (this is no different to some dude who goes to the beach and won't go back and get the suntan lotion or whatever so gets burned to a crisp). Also, once you've got that smell in clothes, it is NON-TRIVIAL to remove it, note. Non-trivial. So if you're some dude who just went to college or moved out or w/e and you aren't good at washing clothes and you get this started you might be stuck with it until you do some serious washing (and possibly clean the clothes-washer too).
I was reminded of this recently when a random piece of clothing I washed had this issue for reasons unknown.