Common misconception #3.14x10^100:
That one or more individuals within an oppressed group happen to side with the oppressor does not make a wrong a right.
In fact, it's discriminatory to think like that, because that means you're reducing the human complexity of the said group to ideas of a few individuals that happen to agree with you and/or your image of that group, thereby depriving them of individuality, agency and nuance, which are important components of human dignity.
On the flip side of this of course you're conferring to yourself the power to judgement of validity of thought and experience, therefore positioning yourself as the arbiter of right or wrong, creating an imbalance of power between you and the said group.
This, so much. It's also a way to diminish someone- to make yourself the arbiter of their experience and even the experience of their entire people.
One of the people I worked with in the past (some people may guess who) did this exact thing about me, and it's one of the reasons we don't work together anymore.
I've had trouble expressing in words how destructive and hateful this was. Your post is so important, I hope everyone reads it.
To make things concrete, that a doctor smokes does not mean smoking is good for you, and if you're basing a positive account of smoking on the doctor's smoking, you're objectifying doctors as a whole, reducing their intellectual complexity to that of one of them that _you_ happen to find agreeable, therefore poising yourself above them all.