He says at one point "You got to get good at what you're doing, and you got to get credit for what you're doing." But they don't blog about it, don't talk about it on the internet. They don't establish a reputation. Then they don't have a fall-back position if they disagree with some stupid metrics that their managers want to impose on the testers.
There are lots of programmers out there blogging about their craft. Percentage-wise its probably a small number, but it seems like it's even fewer testers that do so.
James also says "I have a bunch of Google alerts. If you use certain code words in your blog I will read them. [...] If you say the name of the demon, he shall appear: and read your blog."