It's an interesting question. Is the hat off thing more east coast? I live in Oregon and Washington and I *never* see people take their hats off. I see hats on in theatres, restaurants, church. I think they do make you take your hat off in court, but I haven't been there for 15 years so it may have changed too.
Is taking your hat off when, for instance, you sit down to eat a "old school" manners thing, or is it a "eastern" custom that never took hold in the west?
I think in this case it was a matter of the Mayor and her fellow council members wanting to command more respect for themselves and the city government, and make young people understand civility and things like that. Too bad this kid started getting feisty, if he had just quietly gone out he probably wouldn't have been roughed up - especially with a whole room full of bleeding heart liberals looking on. Unless he was white.