This also explains why some people are concerned about the shortage of programers in general, and shortage of women programers in particular - programming is a high-paying job, so they feel they are supporting a just cause if they are encouraging people to learn programming. Noone feels the same about construction/garbagemen (male-dominated professions) or nursing/cleaning (female-dominated professions), so it can't be something to do with Patriarchy.
I am sure that there are some women who might want to go into construction who are turned away by site managers who don't believe a women can perform as well or that they will be a "distraction" on male-dominated worksites. I am sure that a few more might have been turned away by a few bigots who aggressively treat them as though they don't belong on site.
[edits below] Just wanted to add that it is also easier to fight a fight based on the idea that women are just as smart as men, but relatively harder to fight the fight that women are just as strong as men. Even if many women are stronger than many men, in aggregate men do have the biological advantage with regards to strength.