Hello,
The gender of a person, is not a mandatory information according to the gedcom specifications, so it's not mandatory to have a gender associated to an individual.
n @XREF:INDI@ INDI {1:1}
+1 RESN <RESTRICTION_NOTICE> {0:1}
+1 <<PERSONAL_NAME_STRUCTURE>> {0:M}
+1 SEX <SEX_VALUE> {0:1}
Beside of that, it's not time consuming to click on male, female or unknown when you create an individual. I would not support such a feature at least for the gedcom editor. Francois