Straight men have been socialized to believe that the only affection or comfort that is acceptable to receive must come from a romantic relationship with an attractive woman. They just *can't* understand why they should let momentous, important interactions with women go by.
That's why you've got guys going, "What *can* I do if I can't ask her for her number when she's working?" because they view any interaction as their one precious chance at this only socially acceptable form of vulnerable contact with another human. Pass that up?!
This is also where "friendzone" comes into play. Of course, they're not interested in being a woman's friend. You're not allowed to have warmth and love that isn't romantic. Any kind of non-romantic, non-horny love is GAY.