Sure...but it can change in a matter of seconds rendering this not accurate anyways, plus people can change their 'gender' if they feel like it. I just don't see an intelligent reason why it matters of an anonymous public forum.
People don’t generally change their gender on a whim, so that doesn’t make the info less useful. (Even if it did, trans people are like 2% of the population, so it would still apply for everyone else.) Men and women have different perspectives and life experiences because the world treats them differently. Do you think knowing the age, race, or country demographics would be pointless, too?
I know how biological sex works. I've stopped paying attention to gender because it's not scientific and based on feelings now. I lump it in with religion. Not needed.