Not everybody is underpaid, but among the underpaid, they found men as well as women.
As random illustration, they might pay 200k+-5% to 80% of all level X developers, and the other 20% might only earn 150k+-5%.
I still agree that 'underpaid' is a difficult term here. Maybe the 80% are overpaid? The only hard fact in this example would be that the salary is more skewed than it should be for a 'fair' compensation.
