"What makes the web beautiful is precisely that there are multiple browsers and, if you build things correctly, your sites and applications work in them all."

I work for a company that develops web applications, and I can tell you that the above statement is absolute hogwash. It's a major PITA to implement features such that the user experience is uniform and consistent across all major browsers. In a lot of cases we have had to decide against implementing certain features because they required technologies that were available only in browser X (and X almost always turns out to be Chrome or Firefox).

This is not good for the web, and it does not make the web "beautiful." It's basically fragmentation.