The issue is that, in life, for the benefit of oneself and the general public, problem solving is a major issue.
I'm not trying to deny or degrade other types of intelligence.
They exist and are very useful.
But a dog can have very high social intelligence.
He, however, is [i]not[i/] gunna figure out a logical syllogism, let alone discover the theory of relativity.
There's a reason Aristotle called us the "rational" animal.
That "rationality", or "reason", is generally strongest in NTs.
And that's what those tests (attempt to) test for.
It's really that simple.