I think marriage is a sacrifice for both partners. If you don't know that ahead of time and if your partner is unappreciative of this fact, this is what will happen.
I don't think he is a jerk. He and/or his partner was not ready for the mutual sacrifice.
Well, from his writing, the author sounds like a whining, immature, selfish jerk who hasn't looked for or found decent women in the right places. (Or is looking for a super model fantasy of perfection that won't care if his hair is thinning or he has a pauch.) There are decent women and men in this world willing to committ and compromise in a marriage relationship. (They don't mind growing old with one another either.) The caveat is that most decent women prefer positive, decent men and vice a versa.
I don't know about you, but I would not trade my good marriage (I married a great guy) of 20 years for being single and messing around sexually in meaningless relationships that may lead to disease and/or heartbreak.(Let alone the thought of some jerk sizing me up negatively because I'm old and not a hot to trot young chick.)
As for having children, I thank God for my seventeen-year-old son who doesn't think it's uncool to talk with or be seen with his "fuddy-duddy" parents who, hopefully, have given him a good view of what marriage is really all about.