Some women don't want attention because they felt rejected when they were heavier and never manage to feel comfortable with the turnaround. When I was thin and unmarried, I bought myself a ring to help fend off unwanted attention, which could be quite intrusive and unwelcome.
Even without that baggage (which I do have), attention can be scary. At the extreme end, there's the California shooter who felt entitled to female attention whose murder spree of would have been much worse if someone at the sorority had answered the door.
ETA: here's a RW example of scary attention posted earlier today: