You post on Hacker News, which is a marketing vehicle for YCombinator. Your content helps make it more attractive to prospective startup founders, which lets YCombinator reach their target market with virtually no marketing expense.
Why is sending usage data to Microsoft saying "exploit me", but contributing free marketing to YCombinator is something you do daily?
The world doesn't have to operate on zero-sum principles. There's nothing wrong with helping someone or something out "just because".