It's rather jumping the gun to say that this movie will suck just because of WB's decision. Yes, there aren't as many female directors as there should be and thus the pool of talent you can draw from is smaller, but that pool has some awfully good candidates to choose from. I doubt WB contacts thousands of directors in order to pitch their prized DC properties to, strenuously interviewing each to find the best match. No, their marketing chimps in charge of their asinine focus groups preselect a few big names that are bound to attract the herd, and the studio pitches the project to their agents. And eventually, after a few thounsand dollar luncheons and a pre-contract hearing with lawyers, someone will think to ask the candidate director if they like the source material, or have even heard of it. A 'No' to either of those questions will merely result in someone's PA running out to collate a summary of the relevant wiki page. And then later, if the film doesn't bomb, we'll get interviews from the director saying 'I'd never actually read any but when they signed me on, I read all of it in one night and now I'm a big fan!'
OT: The smart way WB could have done this would be to self-impose a quota on director selection, without necessarily blaring it from the rooftops. Meaning that they interview a few male directors with proven track record for directing movies with good female characters, and an equal number of female directors with same, and find out who can best do justice to the source material. Same process for the writers. Whichever creative team WB came up with at this point, they could at least say they'd approached the matter fairly. The movie could still suck, because Hollywood, but at least they gave it a shot.
As it stands, WB's announcement feels like a magnificent internet-baiting publicity stunt. And thanks to that stunt, if it turns out all the big name directors they're pitching this to are too busy, don't care for that kind of movie, are offended that their ovaries seem to be their primary qualification, or don't care about the source material and are honest enough to realize this will impact their ability to direct it properly, then WB (and the fans) are shit out of luck; they can't go to the very real male talent out there that could do the material justice, because boy, wouldn't that just be a glorious message to send, however they tried to justify it. So they're left with C-lister female directors. Which wouldn't necessarily mean a bad movie either! When I see the paint by number movies some big name directors are making these days, maybe fresh talent of any and all gender are needed, but that's even more of a crapshoot than the process from my first paragraph.
Buuuut overall I'm going to stay optimistic. Ten years back, I'd have said any attempt to make super hero movies and particularly The Avengers would have blown like the H-bomb whether it'd been directed by a man, a woman or an AI built from the collective hive mind of a hundred dead producers, and I've since been proven wrong or mostly wrong multiple times. So whichever director they go with, let's give her a chance, the same chance I'd have given a male director who could have landed such an iconic female character. Let's not assume the only qualification she has is her gender. There probably are quite a few Wonder Woman fans in the ranks of female movie talents. Their chances of producing a good movie are not significantly less than their male counterparts.