I'm surprised to hear so many bad stories about Barbara Windsor. I only met her briefly but she was bubbly and friendly and chatted happily to us, no airs & graces. She got really pally with the director of our am dram group and agreed to be a patron. She seemed nice to me!
I give people the benefit of the doubt if they are considered bad for refusing an autograph or chat when they are out and about and minding their own business. If every time you tried to have a bit of privacy someone came over and hassled you then you'd snap occasionally, even if you had the patience of a saint! I'm more inclined to give credence to stories of what people are like to work with.
I used to be on the fringes of the comedy scene and have seen enough to know that some comedians aren't that comfortable in social situations and use personas for on stage, being fairly withdrawn off it. If someone is inclined to put the person on a pedastal, then it's easy to mistake awkwardness for arogance and a wish for privacy as a deliberate snub.