the destructive thing about this style of writing[1] isn't that the readers like to feel smart or superior to others; the destructive thing about it is that instead of distilling research with an aim to convey useful information, he distills that research with an aim to find the most shocking or counterintuitive possibility, even if the evidence isn't really strong enough to support an 'extraordinary claim' You actually get dumber (well, not dumber, but you gain incorrect models, which can make you look and act dumber) from reading Gladwell's work.
Really, though, I'd argue that most business books I've read had a similar feel. 99% bullshit, and the 1% based on actual science is often based on very shaky evidence.
[1]Gladwell's style is pretty familiar if you've read many business books. Very light, very easy to read; it sounds very authoritative, but is at best 99% fluff and 1% actual solid information. When the fluff is actual fluff (case studies, etc...) so long as you find it entertaining, there's no harm. The problem comes when the fluff is demonstrably incorrect and contributes to you making real-world poor decisions.