Humans are shallow creatures by nature. These days, the 21st century woman has more societal power than ever before in the history of time. Hence, it's now more acceptable than ever for them to be as shallow as men. Women basically want the same things as men in a partner: youth, proportionate height differential, a toned body, strong facial features, facial symmetry, and you guessed it... healthy hair. All of these are biology's way of telling humans which other humans will reproduce healthy offspring. Not to mention society's lack of empathy for anyone that falls outside of this umbrella. Name one legitimate male sex symbol that's bald. Don't worry I'll wait.
She's grown up in a world of Disney princes where not a single one is bald. Even the old man in the movie UP has a full head of hair because I'm guessing the folks at Pixar felt like a bald protagonist wouldn't be as sympathetic to the audience. I bet nobody would've even heard of Fifty Shades of Grey if Christian Grey was a bald guy. It certainly wouldn't have been made into a movie, and if it had I'd bet my life savings on the producers altering his appearance to have hair in the script. So when the hottie you've had your eye on breaks out the vibrator late at night, you best believe that she isn't thinking about the bald guy she works with.
I'm not completely condemning bald guys. If you have strong facial features, a great body, a big d!ck, and can take her to pound town like a champ you'll probably be okay, but since very few men are capable of such things, it's an uphill battle. You're going to have a far tougher time getting her to notice you, and you can bet she's worried about what her friends think about you being bald. Getting women to sleep with you is difficult enough to begin with. Being a bald guy just makes it that much more difficult, no matter how muscular you make yourself. Women want the hunk, not the hulk.