What Jon said.
Every time I try to put my square-peg DD12 into the round-hole public school, we end up with a new round of testing to prove that there's something wrong with her. When she leaves, the need for diagnosis magically disappears.
The factory model of education requires taking round pegs and pushing them through the correctly-sized holes. But because we're talking about highly-variable individuals, even the most conforming pegs are best described as round-ish, and the education factory just selects the best-fitting hole, and pounds the peg through with as much effort as it needs.
Because we know there are enough pegs for which the round holes are a complete disaster, the workers have been provided with a handful of other shapes... square, oval, star, etc. The pegs who "fit" into those holes are even more variable than the round ones, but that's okay, we can just use bigger hammers.
Pegs that are square (gifted) and starred (LD) at the same time make workers frantic, because one peg can only go in one hole.