Well, radical surgery was needed -- it just wasn't at the level of the operating system interface, but rather much deeper in the implementation. For example, ZFS post-dates this rant and certainly represents a radical rethink of filesystems -- but it did this without breaking extant applications. That extant applications were (and are) a constraint on the problem is something that's entirely unappreciated by mid-1990s OS research, which was hellbent on throwing out existing abstractions rather than building upon them.

Finally, in terms of Spring: based on the fact that you are implicitly defending it, I would guess that you never had to run it. As one of the very few outside of Sun inflicted with that flaming garbage barge, I can tell you that it was not at all a pleasurable experience -- and that whatever novelty it represented was more than offset by its horrifically poor implementation. If I ever harbored any illusions about Spring, they certainly didn't survive my first encounter with a machine running it...