I don't think the author is trying to police the habits of others. He's stating his prediction about how factors may change, and what one should do if they agre

I don't think the author is trying to police the habits of others. He's stating his prediction about how factors may change, and what one should do if they agree. Others can agree or not. As to telling people to do the opposite of what the author does, do you have evidence that the author doesn't live on a fraction of what he takes home? By definition, he does. He lives on no more than 50%, since he donates the other half. Per a recent post, he doesn't own a car, and has 19 lbs of butter, purchased on sale, in the freezer. Even if he's living on a meagre $200k/yr after his donations, he's probably still able to save aggressively. And lead a fulfilling life with his wife, children, and hobbies.