Emma Stone might seem like a weird choice for Wonder Woman in just about every single way. Emma Stone is not an action star by any means. Despite the fact that she's been in the Spider-Man series, her role didn't have a lot of action that required her skills. She's also not exactly what you think about when you think about Amazonians. She's far too tiny, and the red hair and pale skin might be beautiful, but it's not Wonder Woman.
The one thing she does have going for her is a whole lot of charm. 'Wonder Woman' was a surprisingly funny movie, and Emma Stone has plenty of comedy chops. The character would have had to be a lot different for Emma Stone to work for the role, so it's best they didn't choose her.