I don’t use babytalk even to babies. It’s unprofessional. I don’t like people doing it around me either. One of my colleagues babytalks to her spouse and I roll my eyes every time and am so tempted to say were you talking to a baby just now?
i don’t think using a term of endearment is babytalk. and hon, as far as terms of endearment go, is pretty tame. while it might be unprofessional for me to refer to my supervisor at work as hon, or him to call me that, a caregiver using it with a patient is just attempting to show kindness, IMO.