I agree that filling your time with non-technical professional obligations and meetings can really destroy your productivity. However, the author seems to think that Tao's greatness is in large part attributable to his working schedule. I'm not really convinced of that. I imagine there are a lot of other things that make Tao really good at what he does. Moreover, I also would guess that for many academic (and probably industrial) careers, non-technical professional obligations, like serving on committees, can be good for increasing your visibility and the size of your network. As with anything, prioritization and moderation are key.