I agree. I think that there are a lot of situations where homogeneous interests/views can preclude interesting conversations, but I don't think HN is a place where this applies.

The reason is, while HN may be filled with all people who like startups--in fact, it may be primarily white males--so many people know so many different things, and have so many different perspectives, that I consistently fin conversations of a higher quality than anywhere else on the Internet.

I agree with the OP that we should try not to limit who can participate in a forum because of high barriers of entry, but I'm extremely skeptical that said limitations actively lower the quality of conversations on a site like HN.