Like I said, bloody idiots.
Lots of posters blaming the cabin crew here.
I have the (questionable) pleasure of seeing a large cross-section of the Great British population in times of stress, and am used to how they react.
Sadly folks, there is a small but noticeable percentage who will make up their minds based on nothing more than a room temperature IQ and a LARRRGE collection of misconceptions, and who will also, when presented with anything other than validation of their own point of view, will do anything, upto and including verbal/physical violence, to avoid accepting the alternative.
These people almost invariably also believe normal rules don't apply to them, and are perfectly capable of e.g. standing up during a take-off role.
Past a certain point you can't actually manage them however hard you try, and they won't be educated, so what do you do?