Stay with me; I'm an equalist.
For those of you who don't know, I like tennis; in particular, playing tennis. Sometimes I even like watching tennis, but, what I don't like is watching Women's Tennis. Now, before you start blurting out words such as 'Sexist' or 'Misogynist' or 'woman-hater', the reason is because I can't stand listening to all the screeching that goes on from the top woman players. I can understand that you sometimes need to grunt/screech on a particularly hard (or poorly hit) shot but when it's done on a drop shot or slice, you have to question whether it's not just gamesmanship. Thankfully Sharapova, one of the biggest troublemakers, has been banned for two years. Unfortunately it wasn't for screeching like a harpy but I am sure the ITF is working on that (one would hope).
I also read an article recently which went on to outline the virtues of Andy Murray's forward-thinking views on Women's tennis getting equal pay / respect. While I agree on the respect part, I'm not so sure that woman should get equal pay. In all of the opens, women only have to pay the best of three sets whereas men have to play five. If they were truly equal, shouldn't there just be a 'tennis open' rather than holding 'sexist competitions' for each gender? I wonder how long it would take for the female players to complain about it being unfair when they're having to compete against the likes of Djokovic or Murray? As was proven, a 200+ ranked man beat the Williams sisters who were top seeds. Make of it what you will. But, of course, that doesn't mean a woman cannot beat a man. I've been beaten many times by women and, as the previous link shows, retired male pro players can be beaten ... maybe that puts a sleight on the win but all I know is I would be beaten by all of them.
In the end, if I don my objectivity hat, it should just come down to numbers. The correct answer to whether WTA players should earn as much as the ATP should come down to comparing WTA revenues to those of the ATP. Simply put: if the WTA earns more then they should earn more or vice-versa. Now that would be fair, wouldn't it?