Yes, it is.
And a lot of well-meaning, liberally minded people sometimes engage in behavior that stigmatizes mentally ill people. If the enlightened people are doing that, you can imagine what it must be like to deal with the other half of the population that is blatantly biased.
I've said here at DU several times that I'm in the closet about my illness out in the real world. A few close friends know and my family knows, but other acquaintances and the people I work with do not know. They really have no use for the information and would probably only use to my detriment. Someone here told me that I should be completely open about it and everyone I know should know about it. In that way I would be helping enlightening the masses and fighting stigmatization. That's really easy to say when you don't have to put your job on the line to do it. My livelihood could very well depend on me keeping this information to myself, and I've got people depending on me.