The actual underlying phenomena is probably that as GPA increase, there is "diminishing returns" to skill. With this in mind, you can improve the lottery by assigning probability of winning relative to ln(x) or 1-1/x, which awards additional hard work, but doesn't give undue credit to the very top performers.

Not exactly sure where the real cutoff might be, that too probably varies with the curriculum, but generally yeah. Either someone gets something or they don't, and if someone gets how to do the work they can be taught and thus will at least do OK learning most other things they care about.

If someone doesn't get how to do the work, but does care, that's probably a medical defect. Hopefully we can treat that someday, if not today. Getting lead out of the pipes and similar efforts would sure help.

If someone doesn't care, that's entirely another matter and we should be more introspective as a society about how to fix it. That's more a political problem than a science problem.

If I remember Google's racial makeup is pretty close to the racial makeup of {x: SAT(x) > 1450}