It really doesn't
Saying that all men and women don't get paid the same is quite ludicrous. First off, do all men get paid the same wage? No. Do all women get the same wage? No. Then how can you argue and say that both sexes should be paid the same? Now I'm going to go a bit further here, and this is where I start to zip up my flame suit...
*finish putting on suit*
Depending on the job, a man could be better suited for it. And depending on the job, a woman could be better suited for it. Most Garbage-men are that, MEN. Why? Because biologically men are stronger. Most infantry are men because they're better it. There is a reason we separate the sexes in every sport.
Now to say a man is smarter than a women or vice-versa is quite ignorant. But so is saying that men are equal to women. Men are better at certain things and women are better are certain things too.
Now why I think more men are leaders in the workforce (checks for any loose buttons in suit)
Why do you think more men are leaders in the workforce? Hmm...what do women look for the most in men? Confidence. All men have to show confidence at some point otherwise they aren't getting any...[i]ever[/i]. Thus the term "grow a pair and do it, damn it". When testicles became a term for confidence/bravery all men are pressured to follow suit...otherwise you're a pussy and you don't get laid and pass on your genes. Throughout human history this has been the case, men had to "grow a pair" and take on the mammoth, "grow a pair" and take on barbarians, "grow a pair" and take over a country, "grow a pair" [insert action here].
I don't know what women have to deal with when it comes to peer pressure (so I'm going to generalize here and cite things from history), but I know they usually make fun of each other based on how they look like. If you look at the first female god statues [url=http://4.bp.blogspot.com/_xmaw2hFIvn8/S9YRS2uUyNI/AAAAAAAAAfY/mhb7K8glHSw/s1600/venusfigs.jpg], "the Venus Figurines"[/url], they represented fertility. Okay cool, men are pressured to be strong and good hunters, women better make the damn babies! Now look at the ideal [url=http://10toptens.com/wp-content/uploads/2013/03/adriana-lima.jpg]female[/url] today...and I guess if you're a straight guy you're probably still looking because what I just said is true; she's the ideal female. If you look at the ideal male, there isn't one, there are two. One is the uber athlete look or muscle dude, and the other is a successful/rich guy, some men are both.
So if you look at society and the social pressures based on the different sexes, men have more incentive to work harder and gain higher salaries, whereas women do NOT. Most super rich women didn't get their money though discipline, and hard work; most of them inherited money from husbands or parents. Or they get money because of their natural beauty (supermodels, movie stars, celebrities; ex: Adriana Lima, Megan Fox, Kim Kardashian). Whereas most rich dudes invented something, created a super huge business...or in other words "grew a pair" and did something awesome, because if you don't...no hot gfs, no awesome car, and your peers think you're a -blam!-ing loser.
So yeah, before you guys get your panties stuck up your sphincter and rage, it's not the men's fault that they get paid more...women like rich guys, so we work harder.