I didn't say that, but pretty is better than ugly in almost every situation, that was the point. Good-looking and usable is better than ugly and usable.
Websites should maximize user experience, i.e. how pleasantly the user feels. Aesthetics and usability contribute to that.
Recreational sites with reference tools. If we were talking about sites like Twitter, then aesthetics are obviously very important. However for productivity tools such as government websites, then usability is far more important as you're not after casual surfers and trying to generate more traffic from them, you're literally just trying to get people to the information they want in the most direct and painless way possible.
Websites should maximize user experience, i.e. how pleasantly the user feels. Aesthetics and usability contribute to that.