That's a failure to negotiate, information asymmetry, and a "Human Resources departments will never, ever pay or suggest a higher price than you stipulate, and spend a copious amounts of time pre-filtering candidates for a job title to the going rate at another company" problem.

Nobody goes "let's knock 18 cents an hour off because they have 2 X chromosomes". If they do, they hide it so well I haven't managed to figure out where they sneak that in as a nosy arse hiring manager.