Because it's more work. Making each outfit fit on every race both male and female is the workload of making 2 outfits instead of one. So that would be 4 outfits if you are demanding the male version fit on all female characters and vice versa. That's why the gender"lock" as you call it, which it really isn't, is addressed at later times. Because it's not simply a matter of toggling it on or off. They have to actually make it fit to the male models. I imagine the big hangup is male Hrothgar and Roe specifically since they don't use a base Hyur skeleton
