That's disingenuous. Smaller communities are better because they tend to be more focused, on-topic, and familiar for their members. When they grow large they can drift off-topic and fall victim to status-seeking and other obnoxious behaviour. The only way to mitigate this (I don't believe it can be prevented forever) is heavy moderation.

HN has survived due to the tireless efforts of some very smart moderators. It continues to creep away from its sense of community, however, and political flame-wars seem to be becoming increasingly common.

Early sites on the internet had not developed the appropriate tools and social norms to moderate effectively against the deluge.