And a good morning to you too, Mary Anne.

The reason for the gender discrepancy has to do with the bipedal configuration. While extravagant mammary development can take place in the empty space in front of the female being, similar enhancement of the male equipage runs afoul of the legs, often in a rather painful way. Accommodation would require more drastic reengineering, notably in widening the pelvis (to female propoprtions!) to provide a larger gap between the legs.

Good physical conditioning is required of StarFleet personnel, including the ability to run as well as walk; but planet-bound Feds have it easier, as I noted. You would, in fact, find civilian males lacking legs, or sporting atrophied legs, who rely on antigravity sleds and carts similar to those used by the hypertrophied females, as well as individuals with reengineered pelvises. As for the latter, given a rough correspondence with the female pelvis, one would expect to find male development on a scale similar to the diameter of an infant's head.

Scary thought, huh?

--Robert