I used to think that people in Silicon Valley were smart people, they just were really smart when it came to their own stuff (i.e. coding, sussing out what kind of software/apps there is demand for, etc). But when they got rich, it both went to their head and they were surrounded by suck ups who would not be honest with them when they said something stupid. So inevitably successful people from Silicon Valley would wander over into other areas and would loudly opine about stuff they knew less about. If they sounded dumb, it wasn't because they were dumb. They just were not talking about the stuff they really knew well, and because of the bubble of fame and riches were not in a position to be self-aware enough to try to learn more before opening their trap.
More recently I've decided that success in Silicon Valley is more just a matter of dumb luck. So the successful people there are not successful because they are particularly smart, they just happened to know the right people, or be in the right place at the right time. Plus, being the kind of self-promoter that leads to success requires a kind of stupidity: the lack of self-awareness of their own limitations that would make it hard for any actually intelligent person to openly talk about their own brilliance.
In other words, I no longer thing they are smart even about their own stuff. I think they're a bunch of lucky dumb-dumbs. To the extent the product that brought them their initial fame and fortune relied upon some smart technical innovation, that stuff was almost always done by someone else (like the engineers they employ), not the guy pushing himself in front of the cameras.
