I'm very sorry. Many of these comments have made me sick to my stomach, too. And also ashamed. (I'm one of the moderators of HN.)

You don't have to be active on HN to apply for YC. There's a technical requirement to have an account, just because YC's software systems were built that way, but there's definitely no requirement beyond that. I hope you'll participate, but if this has been your introduction to the "community" I can understand why you might not want to.