How would it work if it wouldn't? He explains what he means by that. If you spend time and resources on all things the users require and your run out of money and go out of business, everybody loses.
Of course you can take any of the "rules" and take them to an extreme where they become wrong. But I think if you don't push them to their breaking point they are good rules of thumb :)
I think there is also a bit of a conflation of values vs ability. The formulas in the article represent values. Real life adds constraints based on what's possible.
Consider his formula for dev vs user: "user > dev". You could argue that, just as a business is constrained by time and money, so is the developer constrained by time and skills. And yet, the author is happy with turning the greater than sign towards the user in this formula. Why?
It's a priority ranking, not a zero-sum game.