I speculate transference is so powerful and painful for many of same reasons as romantic love (sometimes) minus the erotic component. We came into the world attached, and seemingly have innate needs to seek love, nurture, understanding and guidance. Many creatures we observe have these instincts. Therapy can promise that understanding and care and tap into these primal needs, similar to romantic love.

However a therapy relationship is strictly defined, time limited, our "other" is inscrutable and the relationship asymmetrical. And I'd argue that a therapist is never a blank slate, he always is giving or not giving the client something. I believe there's always a here and now despite what some theoreticians believe. So in a sense, the time-limited therapy relationship inevitably is transference interruptus in my option.