This is a beautiful article, but I feel that it should be read as a chronicle of the author's life experience rather than an analysis on when to have your children.
The age at which couples are having their children is Indeed increasing; this isn't necessarily a bad thing. As the author pointed out, parents are more likely to have time to spend with their children if they've already established a career/source of income. They'll automatically also have better resources to care for them (babysitter/schooling/literally everything else). On top of all that, they'll have more life experience, which should help in the education of their offspring.
Besides, what are the alternatives ? Having your children at a young age has the only major benefit of being young. And if your remain healthy throughout your life, I believe the benefit of being young remains irrelevant.