I believe consensus is that there's a tremendous (like,
wow, tremendous) cherry picking of data and spurious connections to create a catchy engrossing narrative that makes us feel more enlightened and with profound new understanding of the world... But has no actual rigorous methodology or statistical significance. He is unashamedly a
teller of stories, not a scientific researcher. They are fun but should not be taken as accurate. As tptacek says, pretty much all of us have gone through that cycle. He's a great read but should be taken as casual entertainment, more closely related to fiction.
Do not make policy decisions based on Gladwell :-)
Edit : a perhaps stretched analogy - his stories are to me akin to Taylor Swift sharing her story and saying "I practised hard and didn't give up and succeeded beyond my wildest dreams". It's true but not as meaningful or applicable as it may seem - it's insufficient causation and incomplete correlation.
Majority of people who practice hard won't be Taylor Swift.
Conversely,There are many additional reasons beyond practicing hard Taylor Swift succeeded.
It's a compelling narrative but horrible statistical model or understanding of world and causality.