I think people are reacting to what strikes them as odd or of note, but I could be wrong.

I did tell the first therapist I ever saw that I had some weird sort of mother crush on her ( she was my parent's age, straight , I did not know the term transference and I was about 23). I do not recall it being a big deal for me. I don't think it made much difference in the outcome of that particular therapy experience.
I have not had that reaction to any other therapist.

This forum I am posting the link to spends a lot of time on transference:
Making Counseling Effective Forum