Theme parks are interesting, cos of course, as private establishments, they're entitled to enforce rules they see fit. I was at Alton Towers last week, where you have to wear a mask on some of the rides, but not in the grounds. Which i complied with, and tbf it didn't detract from the experience in any way. I would never choose to wear a mask outside, but if that's the rules then so be it, if i don't like it then i'm not obliged to go there

It would be the same with any bonfire events. If they want to enforce such a rule, that's their choice, and if people don't like such a rule then they can go to an event that doesn't have it, or they can use pyro at home
All this naturally excludes people with disabilities, which is fair enough if it'll cause them significant breathing issues