Earlier quoted context omitted.
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 st…
For some of the negative comments, the data actively contradicts their conclusion. Many here seem to think that only an idiot would "invest in a 21 year old with a half-baked business plan." The people posting that have probably made less from whatever they're doing, than PG/YC have from their 21 year old founders.
So it's all about money then, right? Well if you want to take that to the logical extreme then you would take advice from, say, Larry Ellison or Carl Icahn (over PG) because they have much more money than PG does (at this point in time at least). My point is you have to be very careful about putting people up on a pedestal (which is what happens at HN so often) and thinking that their advice ranks over someone who, by the standards of this community appears to be "less successful".