You're simply defining weaknesses of Subversion, not centralized versus distributed in either direction. E.g., we made blame for Git repos in Kiln ridiculously

You're simply defining weaknesses of Subversion, not centralized versus distributed in either direction. E.g., we made blame for Git repos in Kiln ridiculously fast by caching memoized states for each file. You could also do that locally; we happened to do it server-side because it made more sense. There's no reason that an outright centralized system couldn't do that (and indeed, some do, though neither CVS nor Subversion).