This article claims that "critical thinking" should not be taught as an independent discipline - largely because success in any particular area is allegedly more dependent on detailed knowledge of that area. But one of the main reasons for teaching "critical thinking" is to train people to evaluate the arguments and claimed expertise of others in areas where they do NOT have loads of experience or knowledge themselves. As such, it is perhaps THE most important thing a person can learn .... if indeed it can be taught.
But an important point made or implied in the article is that there is precious little positive evidence that those who claim to be teaching critical thinking are having any measurable success. This is certainly an appropriate application of critical thinking to the claims of those who claim to teach it. But it does not address the question of whether or not those skills should be taught if possible. A proper application of critical thinking to the article itself requires us to investigate whether or not the graduates of a "critical thinking" class are or are not better able to identify a charlatan than those who took the "placebo" class. Being too lazy to do so myself I will leave this as an exercise for the reader.