Massimo Pigliucci in Rationally Speaking:
Interestingly, the word pseudoscience can also be used to deflect genuine criticism: oh, you are just throwing pseudoscience at me in order to dismiss what I do without argument, says the ufologist (or astrologist, or homeopath, or…). And of course it is perfectly true that both scientism and pseudoscience can indeed be used inappropriately, just like the term science itself can and has been invoked to prop up all sorts of bad doctrines (scientific psychoanalysis, scientific Marxism, phrenology, eugenics, and so forth).
So the problem isn't with the fact that some people misuse a given term, the problem is whether that term actually refers to something worth talking about. Science surely does; and so does pseudoscience. Things are no different for scientism, but we need to talk about concrete examples rather than conceptual generics.
Unfortunately, Pinker's essay is remarkably short on specifics. It reads like one long whining session against the injustices perpetrated on science by unknown and unnamed postmodernists (the favored bugaboo of defenders of scientism) and religious fundamentalists. Indeed, there are only two specific examples throughout the piece of what Pinker thinks are unfair attacks on science: one by historian Jackson Lears, the other by Leon Kass, former G.W. Bush bioethics advisor.
Kass' piece is indeed a religiously (mis-)informed ramble about the evil of materialism (quite a rich accusation, coming from a political party that has made the pursuit of material goods for their self-selected elite a national platform), so Pinker is right in dismissing it. But Lears' target are the writings of Sam Harris, a textbook example of the excesses of scientism if there is any to be found out there! And therein lies the problem: just as in the case of pseudoscience, the devil, so to speak, is in the details.