I think some individuals may look at professionals (whether it be a doctor, therapist, nurse, etc) solely in their role and not consider the fact that they are more than their job title. They are human. They make mistakes and they can certainly have their feelings hurt.

I am in school to work in the mental health field someday, and I'm sure I'll come across people who don't like me, or say rude things to me. I think the best thing you can do in that situation is to first look at the constructive (or not so constructive) criticism and try to objectively look at it: is there any validity to what they are saying? Is there anything I need to change? If yes, work on improving and making those changes. If not, understand that this hurt is coming from the individual, it is not a reflection of you as a person.