Expressing doubts, as a fan, about a prospective managerial appointment is one thing, and perfectly normal.
As a fan, not giving a new manager of the club a chance and being instantly negative towards him because you wouldn't have chosen him is not acceptable.
Verbally attacking a man for his accent and his appearance, just because you don't think he is a good football manager, is never acceptable.
Expecting people to treat other people with respect and dignity is always acceptable.
The truth is, Beale wasn't accepted and his behaviour only became more erratic as the pressure from fans became more unreasonable. He was never given the chance to prove otherwise and the negativity surrounding his appointment became a self-fulfilling prophecy.