Do you mean "why is it still used in popsci"? I'd wager because it makes people feel a similar way to other pseudo scientific categorizations, but that's mostl

Do you mean "why is it still used in popsci"? I'd wager because it makes people feel a similar way to other pseudo scientific categorizations, but that's mostly speculation on my part. Add in a bit of inertia and the simplicity of it ("let's reduce the cognitive ability of people across the world to a single number!") and, to me, I can see the appeal for others.