Getting back to the article's main attack- It does so by making a logical, if emotion filled, attack. Venture capitalism is still capitalism. Participants work to, primarily, their own economic benefit rather than the benefit of society. (Yes, it's the worst system except for all the rest, but it still doesn't make the most long term beneficial allocations. See: poor funding for fundamental science research.)
Moreover the article criticizes PG (citing his lack of perspective) for promoting a "bootstraps" ideology. It tries to illustrate that the ideology is flawed in two ways: 1. The people who could most benefit don't necessarily have the personal capital (time, knowledge, etc.) to effectively run a startup. 2. It implies that there is only so much problem space that can be effectively addressed at any given time.
This is written in the style of a qualitative sociology monograph. I find it quite compelling, however, I'm not surprised that the crowd here doesn't share my view.