I applied to CMU with a 3.8 cumulative (at a school where AP classes were worth 5.0), 740 math SAT, and 670 English SAT. I was accepted into the school of computer science, after submitting my application in a big red envelope that said "Athletics Department" on it (I was a football player).
Now, I'm a second semester senior with a 3.6 cumulative, I've TAed 5 classes, done 3-4 semesters of systems research, and accepted a job at Facebook (it was between them and Google).
If Caltech would have rejected me (I didn't apply) for being a "dumb jock," more power to them -- it might even be a worthwhile heuristic. I think CMU made the right choice though.
Caltech accepts people who discover their passion for a field very early in life and then excel at basic academics. Some, like myself, fail to take advantage of the academic opportunities and come out much worse than you seem to from CMU. Tech very well would have accepted you, if you had applied, but they would have done it for your demonstrated interest in CS--more likely ACM, since CS at Caltech is an entirely different fish than at other schools--while basically treating your athletics as a null factor. On the other hand, it would have perhaps been a slight negative against you, because athletics took time away from when you could have been volunteering in a local college science lab or hacking some code together. The students who read applications and we who screen them when they apply to sit on that committee are quite serious when it comes to seeking applicants who show a "passion for math and science."
Now, I'm a second semester senior with a 3.6 cumulative, I've TAed 5 classes, done 3-4 semesters of systems research, and accepted a job at Facebook (it was between them and Google).
If Caltech would have rejected me (I didn't apply) for being a "dumb jock," more power to them -- it might even be a worthwhile heuristic. I think CMU made the right choice though.