I have never liked an opening conversation that includes the question about what sex a person is. It seems, to me, the asker is getting ready to pop a person in a predefined box. I like my conversation to be judged on the content, not the age/sex/hair colour of the person making it.
Would a persons thoughts or opinions on a thread that may be inclined to be of a particular gender bend, for example, a question about nailpolish, or car mechanics, be less inclined to be considered valuable input if it is seen to be coming from a member of the sex that topic is not normally associated with ? Sadly, experience tells me yes, this is so.
I prefer the ambiguity as it is now. I like to talk to people and am not worried what sex they are. If they are interesting or enjoyable to talk to, it doesn't matter.