The "bogus" comment falls in a paragraph about ventures where the earnest don't generally win. So the first question to ask is: do the earnest generally win in that kind of academic field? I don't know much about that field, but I'm guessing probably not just because it is too closely tied to politics. If you earnestly persue research, you are likely to find something that contradicts the current political fashions, and end up buried. So in that sense, PG is probably right.

The next question is: is he inappropriately dismissive (or even insulting) to the field over all? Does is have value that he unfairly dismisses? You seem to think so.

But even if so, pretty much everyone needs to be dismissive about a lot of stuff. At least he's transparent about where his blind spots are.