Here's the thing. You'd think someone like Joss Whedon would understand it well enough to say it better, but maybe he's too close to the issue.
Comic fans are sticklers for detail.
Why is that such a problem? Because they are your core demographic with these films. You want to please them, because if everyone's geek friend is ranting about how shitty a new movie is, they won't go see it. Look at Star Trek, Star Wars, or any comic/video game movie, it's usually the same. They announce the movies at a geek con, we spread the hype for them by talking about it everywhere, then they blast epic trailers everywhere just in time for the next blockbuster season.
When they deviate too far from the spirit of the original (or most popular iteration of) characters, the geeks get mad. But! With older characters like Wonder Woman, you hit a problem. The original wonder woman was pretty damn sexist. Just look into the history, it's really a fun read. Her creator invented a key part of the polygraph, or lie detector test, and was a published psychologist for his theories on Dominance, Submission, Inducement, and Compliance. Originally, Wonder Woman could be easily bested by men, and every other issue... no... every issue was her getting tied up. It got better, but she was still only the Secretary when the League was formed, and relatively recently was shown to be one of the most emotional in the DCAU. Certain character traits stuck and others didn't, but the ones that stuck are there for good in the minds of the fans. Even when making a film for the general public, when it comes to the big names, you have to make sure you're still going to be pleasing the largest number you can of the comic fans.
So how do you stay true to Wonder Woman and still keep her PC in 2015? DC has done a great job modernizing her, but that character will never be the feminist commander in chief the SJWs want her to be. It's just not in the cards. She has flaws and her own personality, her own values. You can't force her into another hero's thong.
Incidentally, she's also a godlike superhero with a brilliant military mind who knows to prioritize her battles. You'd think she'd have bigger things to worry about on-screen than the t-shirts of scientists and the fact that "innocent until proven guilty" exists in rape cases.