Earlier quoted context omitted.
"Try to damage Ycombinator"... How?
It's a divisive political topic, and he associated an individual post made on an internal Ycombinator forum with Ycombinator itself. Comments of individuals don't represent the company, and by framing it like he did, he publicly dragged Ycombinator right into the middle of a contentious political debate.
In this case the relationship between member and institution is even tighter, and the desperation of sink or swim is more palpable.