I don’t really understand the point of the article. It seems to be challenging an assumption that being “smart” has something to do with being financially successful. But why would we start with that assumption? Why would we conflate being “intelligent” with being good at making money? To me, this seems as preposterous as asking “if you’re so smart, why are you so bad at playing the violin, or why aren’t you a Hollyw…
The article doesn't really use a strict equality between being "intelligent" and being good at making money. It's more an implication, that being good at making money implies being probably something like "intelligent". Now having this established, your examples of playing the violin and Hollywood stars doesn't make any sense. They are reading the relation backwards. The implication holds the other way round.
If we can't assume that Hollywood stars or concert violinists are intelligent (even if not all intelligent people can be those things), then why would it naturally be so with financially successful people?
The examples still make sense under the premise that the assumption is off.