Most probably aren't just envious. However, those who wrote negative comments weren't afraid to announce seemingly definitive conclusions without enough data to justify their assurance. Keep in mind that the author and his cofounder were interviewed by YC partners and all of the cofounders. While their selection system has flaws, most probably agree that it's one of the best that exists right now. Perhaps they saw strengths in the author's founding team that the author himself had not perceived.

Based on the author's age, I assume he considers this the greatest failure in his life. He wrote this shortly after exiting an educational system that indoctrinates students to believe that success occurs without failures. So his perspective may have been from a point of low self-worth making it difficult to see his own strengths that will help him recover and succeed moving forward.

Thank you for writing about your experience Charlie. I hope the traveling has been beneficial, and I wish you the best of luck in your future endeavors.