because he sounds amazing. If everything you say is god's truth, then I don't know what to say.
My guess is there is something else going on. The narrative you are telling us is almost impossible. Someone torpedoed him in a recommendation letter or there is just something else going on. He has Ivy League stats.
Those stats are WAY above average for BYU, he is an east coast kid, and he has done plenty of extra-curricular. The way you describe it, he is exactly what BYU wants.
My son is still two years out (a soph). Has a 29 ACT in his pocket and a 3.8. I choose to believe he is still competitive (not a guarantee, but competitive) based on what most people are experiencing. Something is fishy with your experience.