It's true that making something people want, if you push it too far, would cause you to make something dangerously addictive. But very few startups are that successful; 99.9% of them err on the side of not making something attractive enough.

So "Make something people want" is like "Get more exercise."

Plus, if you want to try to replace this rule with one that works in that additional .1% of cases as well, it's hard to say what it should be. "Make something people should want?" Then you're on the road to fascism (if you have a lot of power) or failure (if you're just a little startup). I suspect that "Make something people want" is optimal in the same way democracy is. As Churchill said, it's the worst form of government except all the others.