Although it doesn't immediately affect me (I strictly identify as male), my boyfriend and a few of my friends fall outside the gender binary, and there's always this warm sense of approval whenever a site makes point in that section to be inclusive, be it in the phrasing of male/female identified, including a "gender neutral/undecided" ; option, et cetera, it just makes me feel better about the service. And a very similar principle would apply to polls, but I guess few individuals are able to appreciate or grasp the concept. Even a lot of trans* folk I know of tend to get caught up in one extreme or the other, and even knowing non-binary identities exist, seem to lose touch with that knowledge as quickly as they gather it.
So I suppose in short, I agree. That would be more inclusive, and vastly preferable. Though at least the sex/gender field in the public profile is a blank text field?