The canon is hampered by the fairly limited effects budget, as well. No such restraints when it's just text.

I hadn't been, and I am now. I had Cas as a female, and a lot of planned conversations with Dean about the nature of being a parent and how that relies on the social definitions - he doesn't know his parents, he won't raise his kids as his own or even know who they are, and he can't figure out why Dean finds that so upsetting.