Our financialized economy causes bubbles. During many bubbles, the results of a massive, artificial credit infusion reach some sector(s) of the economy. This results in a lot of short-term economic waste, as well as some people getting rich far out of proportion to the wealth they have created. (More specifically, richer than they would've become under similar circumstances in a free market economy without government-backed financialization.)
You can see this when Wall Street traders blow $100,000 on a night of entertainment, and you can also see it on a smaller scale when excessive financing through a VC reaches a company which then sometimes wastes the excess money.
Coming back to this article, Matt seems like a nice, productive guy, so this wasn't really a good example of what I'm talking about. There are some people in the Bay Area, though, who are in the "startup scene" largely to party, socialize, spend lots of money in extravagant ways, and attempt to get rich quick -- this is the "bubble lifestyle" I referred to. I know there are at least a few others here on HN who have seen firsthand what I'm talking about, because it's been mentioned before.
So, when I saw the mention of dual 30" monitors, 2 laptops a year, prime SF real estate, eating out all the time, etc. I was reminded of the bubble lifestyle. Sometimes, for people who are used to being frugal, this kind of thing just jumps out at you. Many hackers are frugal people -- PG seems to be one of them, because I remember him saying something about being impressed that a Yahoo co-founder went poking around Viaweb servers to see if there was any unnecessary use of resources, even though Yahoo was already big and he was already rich.
Before someone downvotes this comment, I want to reiterate that I don't mean to denigrate Matt at all. In Matt's case, it could very well be that the expenditures are worthwhile and even necessary. But I was just reminded of others who are just in it for the lifestyle.