The Captain and crew were 100% correct in refusing the flight. Given a hostile mob environment, the Captain would have been negligent in the extreme and in clear violation of the FARs to allow them on-board the aircraft.
This kind of crap continues because it is too often tolerated. There needs to be a highly visible crack-down on the louts, drunks, and yobos and those people, at the airline's discretion should be placed on a government sanctioned DO NOT FLY list.
Let's see how the jerks like taking the bus and the rest of us can see how pleasant it is to not have those creeps around.