It is absurd to generalize and assume the same characteristics for the whole group. Even when I was traveling I had to deal with this every day and forgive people. Then I kind of understand that it is more convenient for them to just generalize based on the common characteristics they see or encounter their whole lives, or based on their limited views. People tend to focus on the extremes. It saves them the energy to find really unique individuals.
Yeah we deal with it all the time, laziness is a given. I guess I expect it at this point and try not get too worked up over it although it's frustrating. Interestingly, I think if people focused solely on individuals they would have less to deal with as far as maintaining their generalizations.