I can see your perspective on not wanting kids, but for me I want to have children. The only thing is, like you, I don't want to be tied down to a wifey. That's an issue because raising kids is not easy.
And the problem with marrying and mongering at the same time is that the wife won't like that, and the end result will probably be divorce and splitting of assets plus alimony.
Finally, it's hard for me to imagine fucking the same old woman 30 or 40 years from now with her wrinkly face and ass. Of course, I will be wrinkly too and probably bald, but I still want to play, just not with an old, old woman.