Your anecdote illustrates where the anger and frustration around the topic comes from. What you describe is a form of harassment, possibly assault in contexts. I hear women use the term creepy not to describe behavior like that, usually it's about unwanted attention of a sexual nature by a low status or unattractive male.

I might not be tuned in to exactly how the phrase"creeper" is used, but I think it's used to turn the adjective to a noun. Which is even more upsetting and mean, as you assigning a whole, derogatory identity to someone based on actions which are almost always a small percentage of all their actions.

To not see this is being willfully obtuse.