Men simply do not hit on her
Insinuates that she expects men to do all the work which, most women feel that way and most women feel entitled to a man making the move.
Nonetheless 6'0" is not ridiculous since the average guy is about 5'10"-5'11" or so. Odds are she's single by choice and just doesn't like the people interested in her. The same goes for some guys who claim they're "inkels" if you don't like any of the woman that may be into you, you're involuntary by choice. My friend who's short and balding has never been asked out, never been pursued, never has had sex all primarily because he's unattractive.
In hindsight, women shouldn't really feel insecure about most things pertaining to sex and dating because why feel insecure when you have all the power and privilege in the situation? Like I said, erroneous and distorted view of things is why a 6'0" woman would feel insecure about her height.