I prefer therapists with no serious trauma. I had a previous therapist who had serious childhood trauma that he never completely healed from, and it manifested in all kinds of unhealthy ways in our relationship. My most recent therapist, on the other hand, grew up in a loving family, and he was truly amazing, in part, I believe, because of his wonderful upbringing. I'm not saying he never experienced adversity. He grew up in the 50s and 60s, and he was a gay man. I'm sure it was very challenging because homosexuality was not widely accepted back then. But his family accepted him, which probably helped a lot. In any case, I don't think he was ever traumatized. But the lack of trauma didn't make him less empathetic. In fact, I believe it made him a better therapist.
The healthy therapy love I got from him--the kind that's not enmeshment--i think you can only get that from someone with a healthy psyche.