For sure.
> Statistics
Bingo!
YC certainly keeps stats on their acceptance info. They don't accept 99% of those that apply. What % of those that get accepted are over 35, compared to those that apply? What % aren't white men? Multiple founders?
> I for sure don't think the main post is evidence of anything, so I struggle to see how it's getting so popular.
Because OP has a reason to believe they were discriminated against. They ask the question to A.) See if others come forward, B.) Hope/expect YC to produce the statistics we just talked about, either proving or disproving a pattern of discriminatory behavior. And if YC knows they don't discriminate based on age, there should be absolutely no issue with them producing their data supporting that claim, right?