2 and 2 and I gotta agree with him.
1) If it is good enough for the R"Y, it is good enough for me. (not necessarily a reason, but at least a s'neef)
2) It just makes it easier with the kids. Sure you can get them to stop, but this way the problem is avoided completely.
3) If someone is already using "endearing name", e.g. honey, dear, etc...IMO, this is no different.
4) I may be way off here, but I think I remember seeing something in a sefer regarding tznius. (Please don't ask for a mara makom, because I have no clue...for all I know, I just made it up.)