People love to hate Megan Fox, which is one reason not to cast her as Wonder Woman, although I disagree with the hate. Yes, she's almost too perfectly beautiful, but that's no reason to trash her. If anything, it makes her perfect for the character of Wonder Woman. Wonder Woman should make you ask, "is that person even real?" because she looks so incredible. Not that Gadot doesn't pull that off, but Megan Fox could as well.
Ultimately it was more her choice than anyone else's not to take the role. She has been on the record to say, "Wonder Woman is a lame superhero... She flies around in her invisible jet and her weaponry is a lasso that makes you tell the truth. I just don't get it. Somebody has a big challenge on their hands whoever takes that role, but I don't want to do it."