The book is from 2004 so the chapter about 'the modern web' was not very ground breaking anymore, it did gave me a nostalgic smile :)
PG is a good example of violating the Tom Watson quote: “… I’m smart in spots, and I stay around those spots.”
However, it’s helpful that PG writes political stuff. You shouldn’t have to be good a politics to practice it.
If I'd mention Graham's point to our esteemed art history profs they would probably laugh at the man. Especially given how much the approaches and mindsets of actual painters differ. The only thing I'd say is: "Some painters share similar traits with some hackers". But this could be A) literally said about every two subsets of humanity and B) not all of those traits are positive.