“Someone is not a extraordinary intellectual simply because they are a extraordinary athlete.”
That is true.
I would be happier if the academically top universities admitted primarily for academic strength. MIT and Caltech largely do exactly that.
However, whatever the top ranked universities in the US are doing seems to work for them, at least for now.
To be fair, both Tiger Woods and John McEnroe do seem to be very smart people. I have never seen their academic records, but I would not be surprised at all if both were excellent students.