Honest question: What's the logic behind being so utterly rude from the first moment to someone you find attractive? Is it supposed to attract them back somehow?
If you're not an attractive person yourself there are women and girls who are out of your reach. This breeds resentment at an early age, and a weapon of choice, for some, is derogatory language.
Why, because what else can you do to hurt someone so easily without fear of repercussion?
The problem is not just confined to misogynists btw. If you're a man and have an attractive wife or girlfriend the insulting behaviour still goes on, but usually behind your back - these people are generally cowards after all.
When reading the article my first questions were: do these people think there is a real human at the other end, and, if so, do they think the photo is of that human? It's probably impossible to answer that question directly, but putting up a notice similar to "you are talking to a real person, not a bot" and seeing how that affects the behaviour would give some indication, perhaps.