Personality is a vector. Just because you are really high up on technical smarts means nothing in regard to the rest of you. We could simplify it down to a minimal [technical-smarts world] vector where at an extreme end you could have [100 0] being "brilliant, but forgot to wear pants to work today" to [0 100] being "the friendliest, most amazing person you'll ever meet, but they can't work a toaster." Few people are a Feynman. Most of us manage to be midline boring enough we wouldn't make interesting NYT articles.
But, more interestingly, never underestimate the ability of a smart person to seem dumber than they are for their own benefit. We honestly can't tell if he's a rube, a conman, or a mark.