It's part empathy, and part something else (I'll explain in our current PM conversation). But you're right...Dr. Hetalc is a man who cares deeply about his patients, and wants very much to save lives and ease suffering. He finds "doctors" like Moset completely reprehensible and horrifying.
And yes...it's very interesting how similar-yet-different Cardassians and Vulcans are. They both come from desert worlds, and they're highly disciplined and conformist peoples...and yet it shows in SUCH different ways.