Because PG's essays are intellectually uninteresting and often times mistaken (which is a nice way of putting incorrect). If the essay's didn't have his name on it, they'd be harshly critiqued when they get past around these parts. If you're looking for academic perspectives, especially around the subjects of rhetoric and debate, there is absolutely nothing worth reading in those essays.
Quite frankly I find it annoying whenever I see someone linking to them. It's junk food for your mind, with some Silicon Valley sprinkles on top.
I mean look at this gem in the linked essay:
>So although not knowing how you know things may seem part of being human, it may not be.