For me, flapsforty has it pretty much right. I have never understood the logic that allows people to feel it is acceptable to behave discourteously to crew for events and circumstances that are completely beyond their control - the equivalent of being rude to a waiter about the shortcomings of the chef.
The original Captain was unavailable for medical reasons (according to the press report shown). This kind of unforseeable event cost VS many hundreds of thousands of pounds and a certain loss of good will. At the same time, these things happen, and a certain degree of forbearance amongst the passengers would be appropriate. The Captain involved in this appears to have been a "substitute": Neither he, nor his crew, would have done anything "bad" to these passengers, and may not even have been present during the original delay. I find myself wondering what Mr Warshaw felt he was achieving with his ironic clapping and jeering. Neither action would get them airborne any more quickly, nor would it enhace the travel experience for fellow passengers or crew: In fact, quite the opposite. In short it would achieve little except to feed Mr Warshaw's dubious sense of his own self worth.
In a serious delay, the majority of customers will accept their bad luck with equanimity and reasonable humour, and reserve their complaint for the airline customer relations department, if there is genuine fault. There are always a very small minority who choose to speak, and behave, appallingly, often under the impression that they speak for the majority. If not handled correctly, they can make a bad situation much worse. As cabin crew, I'll do everything I can to help the majority, who deserve my time and attention, and I welcome any action by the Captain, or indeed any authority, that silences the troublemakers.