Your point about Stanford having a larger-than-average proportion of 'extremely gifted' kids is reasonable. Perhaps the smartest 20% at Stanford are drawn from the smartest 0.1% nationally.

But I think you're too dismissive of this part:

  The professors Horowitz interviewed largely back up this theory. "You hear 'students with disabilities' and it's not kids in wheelchairs," one professor told Horowitch. "It's just not. It's rich kids getting extra time on tests."

If you read the statement charitably, the professor only pointed out two things that are probably true, which I paraphrase below:

- most people, when they hear about students with disabilities, imagine physical disabilities

- the professor has seen that a sizable proportion of students classified as disabled do not require accommodations

Now, we could argue about what are reasonable accommodations and which are not. This is where I'm interested to hear your perspective.

I assume you are in favor of these two:

- kid needs wheelchair and a ramp, so kid can attend class

- kid needs glasses, so kid can see the whiteboard

I assume you are not in favor of this one:

- kid cannot find the derivative of 2x^2, so kid is allowed to use a CAS calculator for Calculus 1 exams

What do you think about this one?

- kid can pass the English Composition 1 exam, but only if given twice as much time as other students