Why would you do this on a bus?

Today I had a run in with the weirdest passenger ever...
Most of you know I drive a bus on Saturday as a second job.

Guy gets on my bus and sits on the first row of seats, right side of the driver, with a constant angry look. After about 3 minutes, he comes up to me and says "Why do you do that?"
I asked him what do I do and he asks why my seat goes up and down constantly.
I explained that's how an air-ride seat works. Buses and trucks have them, so drivers get an easier ride and less stress on their back and spine. The seat bounces up and down to absorb bumps and reduce the strain on your back, so most drivers set up their seats on the softest and bounciest settings.

Then he told me "Stop it, it's annoying and I'm getting very angry"...
I told him it's how I've set up my seat and I'm not gonna change it because of him. I have a job to do. If he doesn't want to look at me, he can move to the back of the bus, or catch the next bus.

He then started shouting "Stop the bus, I want to get out! Let me out of here!" and went as far as trying to pry the doors open.
I stopped as I didn't want to make a scene, or write annoying reports and let him out and as he was getting out, he told me he'd report me to the bus company...

What an asshole... Who does that?! I've had drunks, bachelor and hen parties, crazy footballers, but nobody has shouted at me for how I set up my damn seat... Why would anybody care about that?