I agree 100%, and probably more, with Prolix.
More than that, healers are abusing the system: even when told to back off, they keep doing it. ICly, they would be paid with a blade through their face. But one can cast spells on someone else without any risk of retaliation, so why bother?
In fact, it's not only valid for healers. Some guys chase you around trying to read your mind, or do some other stuff, and you can do nothing but log off to avoid it. Great! ... while we all know the simplest way to interrupt a spellcasting.
I've never been harassed by PLers. Only by mages, and mostly healers.