Your argument is that the majority opinion is never psychopathic? Technically, if you were referring only to insanity, I might agree that an operational definition of insanity is anything that a majority of the population doesn't believe. But that doesn't mean the view is not psychopathic.

This definition of insanity might also not be correct. After all, was Galileo insane because most people (assuming they followed the church) didn't agree with his views?