Perhaps "smart" is too un-nuanced by conflating the real performance of many types of intelligence areas (social, emotional, political, spatial, logical, etc.) into a singular narrow attribution based on brief interactions? (Also yet another example highlighting where language constrains thinking.) And therefore the overvaluing of maximizing possession of one strength at the detriment of avoiding complementary strengths in other areas? Effectively, a personality monoculture where greater personality diversity would likely have tangible benefits (leadership, sales, marketing, strategy, design, etc.)
Smart is a hard thing to talk about. Like the concept of "quality". There are hundreds of different kinds, and I can't really describe it, but you and I both know it when we see it.
I can forgive them for being overly broad with "smart". You're also right that it's not one thing, but it's just hard to talk about, because it's like a wet bar of soap.
The human brain is insanely good at consistent dimensional reduction. Our conscious interactions struggle with the same task; it's Herculean to approach general purpose ordering in many-dimensional situations.
IMO "smart" is more of a social role than anything else. There's a specific sort of behavior that you have to do in order for people to think that you're "smart". Like, take George W. Bush for example - he's about two standard deviations above average in intelligence, but his public-facing persona lines up much better with "regular guy" and so people misunderestimate him.
You can find similar examples from all sorts of public figures - when you dig into them, there's way more there than their persona suggests. Kanye West, Lady Gaga, Marilyn Manson, Dolph Lundgren, and more.
