The problem with Gladwell is that many or most of the anecdotes he uses have been used by others to draw different conclusions (how many times have you read about the Tenerife disaster for example?)

I don't think Gladwell pretends to be doing science, but what he does is worse than "non-science", it's a kind of charlatanism. He builds a thesis and then hand-picks anecdotes to fit his preconceived narrative.

That's how chain-letters are made. (And his talent as a writer makes it worse.)