At a guess, it would have taken the whole "role play game" thing to an insanely realistic level, or what I mean when sober is - it isn't as detailed a game as that.
Looking at it another way. So in Skyrim you can get married, nice touch actually and perhaps one Bethesda didn't think would be as popular as it is.
However, let's look as an example at a different game - GTA San Andreas. Now in that, there was a hidden mini-game where you could have six with your girlfriend.
All evidence points to it being a joke thing the programmers put in, the studio soon closed it off but there was quite a few protests at the time at such content being there.
Bethesda could have easily extended the marriage thing to say have this option, but it would have opened a huge can of worms. The game rating, and it would have alienated a part of the target audience. Well ok, possibly not alienated, but it would have no doubt been all over the internet, by silly people making nudge nudge remarks about it, and would have overshadowed the whole game. An unwelcome addition really.
So no nookie, no kids, but she will call you my love and make you an apple lattice pie. Excellent surely
