The author sounds burnt out and bitter. I get that he tried really hard and didn't quite make it as far as he wanted, but this reads like he's holding onto a lot of resentment for no good reason.

My experience with doing competitive math and programming stuff was generally quite enjoyable even though I never did the best or made it to an ivy league school. I'd still encourage any kid who's at all interested to try them out. Solving puzzles is fun! Who cares if learning number theory is "useless". So are video games, football and chess.