I've never really had an issue approaching any woman that I thought was hot, but I know a lot of guys who did. It was always the same arguement I heard.
"She wont be interested in me" or "She's well out of my league" or "Bet she's taken". Now i'm not knocking any guys for thinking that way because it could stem from shyness, which is nowt to be ashamed of. I can be shy too. Honest.
I always thought, if nothing else I can make a mate here and even if she is taken, she'll let me know. I did go upto one hot girl and only after saying hi did I notice she was upset. So I changed tact and gave her a shoulder to cry on. Turned out that all of her mates had pulled and left her standing on her own all night and the only attention she'd received was from a drunken midget
Lastly a co-worker I knew couldn't find romance because her beauty intimidated all the males around her. She found it highly frustrating and admitted to being very lonely, she'd been single for two years. Eventually she did snag someone after 6 months of chasing and he was a handsome lad at that, albeit a little shy and intimidated by her.
