I have yet to read any of the other comments, so this is right off the dome, but I imagine that most of them think that they are just sending a compliment and brightening someone's day.

I doubt they imagine that the girl is gonna sprint across the highway at 75 miles an hour, rip the door of their car, shred their blue jeans like a wildcat and start fucking them like an insane, rabid mongoose.

Maybe they should. Maybe that would inspire the fear needed to stop catcalling?