It's not "biomechanical". There's a ton of detail in it. You'll see. Frankly, I think it looks better turned off. :lol
That being said, every time one of these comic book movies come out, all the hardcore fans complain about how the designs are different from the comic.
They don't make these movies for hardcore fans. You guys buy the comics, you'll keep buying the comics and the comic related merch even if the movie sucks. You're on-board already. They don't need to win you over and they don't care about pissing you off. You're not going to suddenly hate Green Lantern, or Thor, or Iron Man, or whatever because you hate the movie.
They make these movies for Soccer Moms and NASCAR Dads to take their kids to. People that wouldn't normally watch cartoons or buy comics. They're trying to bring it to a whole new audience, and make it accessible. They think people aren't going to buy the Power Battery looking like it came from the Polar Express, and frankly, I agree.
Look at Iron Man. They strayed WAY away from the comics, but those movies are mega-hits, and selling comics. Helping us nerds look cool.
They get a new generation pumped to pick up the comics. The movies drive the publishing, which drive more movies... etc.