Perhaps I should have put "damsel in distress" in quotes. It describes the attitudes of those behaving as "white knights", not that of those calling them out on it.

"Harassment" describes a very broad group of behaviours. It's fine as a descriptor for that class of behaviour, but that doesn't mean specific terms to describe specific behaviours shouldn't exist. That's like saying you shouldn't use the term "knock" to describe premature ignition when "engine trouble" also describes it.

That said, you're correct in saying that the use of the term tends to be sexist and dismissive towards women. I don't have a solution for that.