100% of the passengers I've kicked off of flights have been flying to, or out of, NYC. None out of other city pairs. Zero. Hmmm, what's the common link?
It's a weekend. Holiday weekend. Flights late. Folks drink. Sometimes it's part of the problem, sometimes it isn't. We weren't there, we don't know.
We do have the testimony of other passengers that some of the passengers got out of hand.
I love the 'just make nice PA's' and it will be better. I'll try and remember that next time I see video of riots at soccer matches - "oh, if they'd only make nice PA's and explain themselves everything would be better."