bald guys ?

one explanation could be as follows:
in general human beings like and get attached to people that resemble in their behavior and looks to the care givers that they had in their early childhood
also

that said, girls generally are more attached to their fathers.
they naturally tend to look for mates that are similar to their fathers in some way or the other are similar to their fathers
generally when girls reach an age so as to find mates, their fathers have become old and bald
and so they find them more attractive

a second prescriptive could be as follows:
a basic knowledge of social psychology says that we tend to notice people which stand out from the crowd who look different
and the bald feature of men is easy to notice and difficult to hide
this makes them more prone to being noticed

another explanation could be as follows:
people who are in a way not very good looking try a little harder to compensate for their lost self confidence and attribute for social status with some other attribute
so they naturally tend to try a little harder
and so they are likely to be much better at whatever they do.