> I don't think the people who like it are dumb
I don't think that's quite what the parent was saying. It's not that BBT is a show for a dumb audience. Rather, BBT is a show about supposedly smart characters, with a writing staff that doesn't have anyone sufficiently-smart-enough on it to be able to accurately depict the thinking process of genuinely smart characters.
You can't, as someone with an average IQ, really write the internal monologue of someone with a much higher IQ. You can probably capture their personality, but you can't solve problems the way they solve problems (or write characters who do so) without, at least temporarily, actually being that smart.
This is an often-discussed aspect of writing military fiction: it's basically impossible to come up with the sort of strategic masterstrokes that a famous general would come up with, without yourself being a famous general. You can bring together ten lesser strategists and ask them to knock their heads together, and you still won't get a brilliancy† out.
† https://www.chess.com/article/view/how-to-play-a-brilliancy
Most people who write master strategists in fiction end up just doing one of a few main things:
• they crib all the "clever moves" from well-known historical battles. This limits you to just, essentially, writing history over again wearing a new coat.
• they get an actual master-ish strategist to consult. You see this in, for example, sports anime about chess or Go—the author usually relied on input from a high-level professional (but not master) player.
• they just make the characters' abilities entirely informed, rather than explicit. This is your Sherlock Holmes story: you can see what they came up with in the end, but you don't get any insight into how they went about putting it together. The author just decided what the solution was, worked backward to what sorts of clues would lead one to that solution, and then decided by fiat that the protagonist would notice those clues.
The whole "rational fiction" movement is basically about avoiding doing any of the above.