They actually get paid more per hour when you break it down, having to work 60% of the time/ sets that the men do to win a full sets match. That could also be argued as unfair when placed in just one specific context.
Fair does, mate, but when you signal you're desperate to unload players people take the piss. Public face: we are all happy with the squad; Private face: get rid of the underperformers. Now, how you do that is above my pay scale!