We want to be looked upon as smart and as having thoughts worth saying. One of the fast ways to do this is to beat another smart person in a rhetorical fight. But smart people are hard to beat in such fights because, being smart, they tend to think correct thoughts. Therefore we have a subconscious motivation to misread them and fight against what they did not say. This is the only way someone without extraordinarily high amounts of expertise and insight can "win" against Paul Graham in his primary domain of thought. There's a real social pressure for people who comment on other people's thoughts to create straw-man lookalikes of the thoughts rather than to address the thoughts themselves.
