People value intelligence and will apply that label to themselves even if it may not be true. It's a hard thing to measure though IQ does it reasonably well. To those who have a high IQ: what is it like? Can you pick up any book, read it, and understand the gist with minimal repetition? Can you infer solid and accurate conclusions based on a small amount of evidence? Is any subject or discipline up for grabs or do you have to have a keen interest in a particular field in order to flourish? What is something you are able to do that you know is because of your intelligence -- the proverbial 1,000 pound deadlift of the brain, if you will.
There is no point to these questions other than curiosity.
Also, side note. People value intelligence when it benefits them. Nobody likes being on the receiving end of an intellectual beat down but plenty enjoy being on the side that do it. See modern media and it's portrayal of "smart is sexy". It's almost always a smart character using their brain to outwit everyone else in the room while showing off to a love interest. Dr Who has done it for decades, Sherlock did it, Disney and Marvel have done it, and always with a support group in tow made up of pretty and pretty dumb characters who love to see their smart champion play wordsmith with everyone else and emerge as the biggest brain in the box. When someone else is smarter and this gets used against both the champion and his cheerleaders then suddenly smart isn't sexy any more, it's creepy, or weird, or ominous, or whatever.
tl;dr People value intelligence for selfish reasons.
Holmes's only love interest is an afternoon at the opium den, he hates women. If you read the books the guy is 100% aspie savant. He has two operating modes... pursuit, and coked off his ass.
In this case, I think he was referring to the hugely popular on tumblr show called literally Sherlock that was highly praised for its "portrayal" of an intelligent character.
It had a final season so bad people literally memoryholed it, rewrote history to call it always trash, and forget that its the only reason Benedict Cumberbatch got famous, but it was one of the leading examples of "smart is sexy" a decade ago.
Everyone likes it when Sherlock Holmes does his thing on someone else's or has a flair about his abilities. Telling someone that you know their walking route because they stepped on the red mud at the construction site two blocks over in a single sentence sounds pretentious to them.
But aim it at them, and they get scared. Now have a German accent and facial response. Suddenly everyone thinks you're planning their doom and not Scooby Doo.