Why don't guys approach my friend?

my friend's stunningly beautiful. many girls tell her that she's gorgeous, and many guys tell her that she looks beautiful or hot. but she still doesn't have a boyfriend. guys don't approach her or ask her out. today was a great opportunity for guys to ask her out. my friend walked into the building in a jacket and pj pants. nothing slutty. there was a large group of guys staring at her and turning their heads toward her. she sat across from two different guys. they turned their heads toward her. i heard them talking about how hot she was. they sat there for while, staring at her. they stood up. i was hoping that they would say something to my friend. but they walked out. my friend was really disappointed. how do i reure her? i know guys are not repulsed by her looks or anything.