[krastanov]

It is definitely not that straightforward. You are probably right when referring to the top talent, but for the majority of the workforce it comes down to negotiations and raises. There is plenty of guilt to be spread around for everybody involved (like, "why don't women negotiate more"), but there are also known well-measured biases against female engineers (SWE has a neat "research" page listing reproduced studies on the topic, same with Project Implicit).