PG's assertions based on anecdotal or no evidence used to be one of my main complaints about his older essays. Though I often still agreed with his overall points, I didn't like how he would reach them. Having said that, it's definitely hard to toe the line between succinctness and backing up your claims.

But, as it turns out, he's gotten a lot better about substantiating his claims. I'm tempted not to substantiate my claim after that sentence, but his presentation at startup school last year was pretty much all about the evidence.