Danielle..
I kind of see where you're coming from. A bit. However, I'd say that the fact that Hasbro said that being female is merely a characteristic, like blue eyes or wearing a hat or glasses, suggest that they believe that the default is male. You know, like society does. I would suggest that having male as default as the basis of a game for small children isn't teaching them good things about women.
If formative images of women are that they are other than default, then what might that mean for the future? I don't think anyone is suggesting that Guess Who? is some great misogynist conspiracy, targeted at making small boys into rampant MREs, but the small things often build up into a bigger picture, don't you think?
The Robinson's golly was a small thing in the grand scheme of racism, however, when we look at it in the wider context of how people view PoC, then it takes on greater significance.
Plus, of course, most people are capable of being pissed off about the big things, while also recognising that the small things don't help either.