I've got no time for this kind of talk. Some geniuses are very affable, public, people , some are very private, reserved, aloof.
Rossiter's generation is very different from today's actors. Todays actors are more like advertising PR men, the kind of people that Reginald Perrin was mocking. He was a true actor and mind, one of the Hancock brilliant kind.
If he was unpleasant to others, it was probably a reaction to the acknowledgement that, one day, it would all end, that wars, famine and hut were still going on outside of the bubble of entertainment. Some actors come from comfortable families, upbringings, others don't.
I'm sure that if he'd been born in to a Los Angeles acting family and lead that life, there wouldn't be this talk because he wouldn't feel quite so different. Acting is a businesses where you can control a situation for a short time on stage or screen, within the rules of the director, but life's often not like that. He was very popular with me as a viewer- he was the Rik Mayall of the time in my view, a well spoken man who created an appearance of anarachy in some ways- but it was a social study in Rossiter's case more than anarchy. He was making important TV.