The main problem regarding gender balance in nuTrek is that they took the characters of a show from the 60s and transported it into the 21st century. That's why you have the black girl in miniskirts still acting basically as the receptionist (and love interest), but nothing more substantial.
Then there's the sexism coming from the writers, because they think the story and script are elevated by threesomes and women dressing down for no reason during a dialogue.
Deep Space Nine had better gender and ethnic balance.
Voyager had better gender and ethnic balance. Heck, Captain and chief engineer were finally women. Only in season 4 they lost the ball when they introduced Sex Object of Nine in skintight catsuits to boobs the ratings, err, boost the ratings.
Let's not talk about Enterprise, because that was silly. Hoshi, the receptionist again, and T'Boob. And then the mirror universe episode where they suddenly run around with bare bellies to sex it up.