I'd rather they focus on things that wouldn't bite us in the ass later on. Resources are finite. Adding two more character models will only take those resources away from things that could benefit everybody instead of just the few people who would play those genders such as more glamours due to having to cater each and every glamour to more models inflating the amount of work needed from the already overworked dev team, expansion of customization options onto the races/genders we already have in the game who really need an upgrade, etc.
Them adding the other genders isn't just asking to add something else, it is also asking to take away what we would have gotten if they didn't cater to the whining.