I've gone on at length with these examples because I think they also run counter to another point I have seen made about Gladwell's writings recently: That he does nothing more than restate the obvious or banal. I couldn't disagree more here. Indeed, to his credit, what he writes about is the opposite of trivial.
If Gladwell is right in his claims, we have all been acting unethically by watching professional football, and the sport will go the way of dogfighting, or at best boxing. If he is right about basketball, thousands of teams have been employing bad strategies for no good reason. If he is right about dyslexia, the world would literally be a worse place if everyone were able to learn how to read with ease, because we would lose the geniuses that dyslexia (and other "desirable difficulties") create.
If he was right about how beliefs and fads spread through social networks in The Tipping Point, consumer marketing would have changed greatly in the years since. Actually, it did: firms spent great effort trying to find "influentials" and buy their influence, even though there was never good causal evidence that this would work. (See Duncan Watts's brilliant book Everything is Obvious, Once You Know the Answer—reviewed here—to understand why.)
If Gladwell is right, also in The Tipping Point, about how much news anchors can influence our votes by deploying their smiles for and against their preferred candidates, then democracy as we know it is a charade (and not for the reasons usually given, but for the completely unsupported reason that subliminal persuaders can create any electoral results they want). And so on.
These ideas are far from obvious, self-evident, or trivial. They do have the property of engaging a hindsight bias, of triggering a pleasurable rush of counterintuition, of seeming correct once you have learned about them. But an idea that people feel like they already knew is much different from an idea people really did know all along.