you questioned shows requiring extinguishers, you got an answer, your objections to the procedures don't need justifying, anything is 'optional' unless the particular show says otherwise
I don't carry one myself, but our local shows here
suggest folks have an extinguisher, and most vehicles have them - it's common for it to be 'displayed' on the passenger side floor
myself, in the event the electrical under my dash started sparking, I wouldn't be reaching for the extinguisher, I'd have my foot on the brake and be heading for the side of the road

Bill