> than other people with the same years of experience (or
> less) is insane. I can admit that they're better engineers
> than me. That's why they get the big bucks.
Sure, and that’s just fine and sensible. But you might feel differently if they were in fact worse engineers than you. Which is the position that women are in, unless you think that sexism and gender bias doesn’t exist.
In a sexist and gender biased system, the pay gap is not “someone is making more who is better than I am” it is “I am making less than everyone else outside my gender group whose experience / talent matches mine and some who aren’t even as good as I am.”
Can you see why that might be a little less fun and why you might feel frustration towards a field structured that way?