Female sex roulette
Shockwave at various points expresses surprise they aren't extinct, which would seem to imply females were thought to be no longer part of the Cybertronian race.
While at the time a decent (though certainly not perfect) explanation for the scarce appearances of female Transformers, it didn't stop more females from showing up in the movie and season 3.
This spares the Decepticons' lives in the final battle between the two forces.
This certainly casts an odd light on the matter of Transformer reproduction (and on the manga author).
In almost all cases female Transformers are portrayed as comparatively more graceful of form, and more rounded and curved in general, than their male counterparts.
There's still a long way to go, since they ARE still pretty dang rare compared to the "guys" and as Mairghread Scott pointed out, this can inadvertently make any given female Transformer and their stories seem like a comment on real women.