I think it is good advice as long as you don't have a REAL passion. Once you have one, it is spectacularly bad advice, because in this case there is just no way

I think it is good advice as long as you don't have a REAL passion. Once you have one, it is spectacularly bad advice, because in this case there is just no way you cannot follow it, and trying to do so is just hurting yourself. Of course your passion always also involves things you might not cherish as much, such as marketing, sales, etc., but you'll endure that if that stays just a tolerable part of what you do.