The "Sex" question in user profiles was added as part of T1139: Internationalize Phabricator. It is a relevant question for proper localization in many languages, but not in English. Therefore, in the context of an English-only instance, the question feels odd, since we are not going to do anything with this information.
If a general solution for Phabricator is not viable or not a priority, which would be the best way to get rid of this question in our own instance?
The original request, for what is worth: http://fab.wmflabs.org/T139