Like you, I enjoy programming a lot, and I consider myself lucky that I get to spend most of my time on it without these distractions. It's rare to be in a field where you can do what you love without being forced to take on the other stuff over time.
Seriously I think it's more about you overestimating the actual time you clocked programming than about Rob Pike.
I'm 43, working mostly as an IC since 1997, really doubt I spent more than 15k hours properly programming rather than fussing with customers, estimating, documenting, testing, screwing around with infra or reading.
2) I mean, if you are doing it "right" ;P, testing is also coding, as is "screwing around with infrastructure", and while I admit reading isn't always about programming... but shouldn't it be? I can recommend some blogs and wikis and mailing lists ;P. Like, the practice of playing tennis involves more than just hitting the ball: at minimum, you also--at least sometimes--have to spend some time retrieving the ball once hit.
I think they took the practicing part literally. In my eyes, any work related to programming is programming. I'm sure Donald Knuth has spent over 30,000 hours working on "The Art of Computer Programming".