I have not been single for 40+ years. I started dating when I was 16 years old. Met my husband when I was 19 years old. Got married when I was 21 years old. My husband thought (and thinks) I'm beautiful. Thanks to him I now have beautiful daughters. 1 daughter is married. 1 daughter is divorced. 2 daughters are single ON PURPOSE. 1 daughter is developing into a beautiful young woman.
I find the question about WHY beautiful women are single an interesting one. Actually, as a woman, I sort of find the question insulting and cruel. It's as if saying to a woman ... if you're ugly WE KNOW WHY you're single. That is not cool!
Also, what's wrong with being single? I am reminded of a quote by American actress / sex symbol / beautiful woman, Marilyn Monroe who said: "I'd rather be unhappy alone than unhappy with someone." I think she spoke from her personal experience.
Many women deemed beautiful by our society's standards probably get very annoyed and aggravated at the question: "You're so pretty. Why are you still single?"
For those women I would supply the response: "A man don't choose a woman. A woman chooses a man. So far the handsome and ugly men are not worth choosing? And don't tell me I'm being picky and setting my standards too high!"