Correction, never criticized pregnancies in the games as being only or mostly for female characters. As you stated in your post and if i must be more specific, at this point in the game cycle there seems to be a focus of female PC pregnancies or if you're not female you still get stuffed and not so much as you doing the stuffing. Who's to say a year from now this reply will no longer be valid. My reply also wasn't a complaint.
There are several reasons for this. In no particular order:
- If Steele is the mother, then the fate of the eventual child rests in her hands. The handwaved nursery helps avoid the rather nasty ethical issue of "hey, what happens to my kid when he or she is born in the middle of a hostile jungle / war zone / horrifying scrapyard wasteland / creepy cow planet?" Some PCs might be okay with sowing their seed across the stars, but others might not be, and the game really doesn't have support for "stay somewhere and become a responsible adult" as an option at present.
- From a writing and programming perspective, it's easier to show an impact with a PC mother. If the PC is the father, you either have to have a temporary or permanent companion system or you need to somehow write the fact that the PC became a parent into world events. Given how quickly a male Steele can arrive on a world, have sex, and leave, it's entirely possible that the PC could father a child and not even be aware of it. And even if Steele does stick around... what do you do? Do you write an event where some random local you knocked up comes and says hi? Does the player meet a half-whatever that looks remarkably like him? It's a complicated problem.
- There is choice and player agency to be gained from female pregnancies, whereas there isn't as much to be gained from becoming a father. As a mother (due to a random encounter, not a large narrative arc), Steele can decide how he or she reacts to that. Is she happy? Resigned? Upset? There are stories that can be told there, and the player can then make choices based on them. But as a father, because of the inevitable physical distance between Steele and the mother and child, it's a lot harder to make the player's choices matter without stomping all over the choices of the mother, which many people would be uncomfortable doing. Now, of course, you could solve this with an extensive writing project and a relationship with the mother, but... now we're moving out of the realm of random encounter offspring.
Essentially, for random event pregnancies (the predominant kind we have at the moment), female pregnancies are easier to write, offer more to the PC in terms of character and story development, and are less morally questionable. When we get some children from longer-term relationships, I suspect we'll see far more options, but for now... I would expect incidental offspring to be more of a feature for female captains.