What's the Opposite of the Sensible Technocrat?

I don't think I understand this argument from Atrios. Although I'm pretty positive I disagree with Brad DeLong about economic policy being more left than he is, this is an argument about expertise. The Sensible Technocrat is an ideal: someone who makes policy based on knowledge. If your argument is that the Sensible Technocrat is not to be trusted, that's an argument against the body of knowledge the technocrat uses, isn't it?

I'm for pragmatic policy. If your argument is that it isn't working, then that's not pragmatic policy and you're not arguing against it.