I wholly disagree. All but a small number of the happy, successful people I know in highly challenging or intellectual positions have families and children in later life.
I do know several people who avoided dating altogether in pursuit of some other goal and, honestly, it hasn’t turned out the way any of them expected. One had a small startup exit but is now trying to play catchup on life with a lot of regrets, basically.
I think this advice is similar to the advice to young people to drop out of college so they can start companies or follow some passion: You don’t hear about the vast majority of students who drop out and regret it, you only imagine the Bill Gates of the world who drop out and achieve their dreams. For most people, the advice doesn’t get them closer to success or happiness like they imagine.