The United States isn't a democratic government. Democracy is the mechanism by which we choose our representatives, but our form of government is a Constitutional Republic.
These type of comments seem to be common in discussions on sites like HN, perhaps because it is so easy to make them, when commenters are hidden behind keyboards. Commenters make broad, general, often philosophical statements that do not address the specific points of discussion. Comments argue about abstract notions, failing to cite specific, concerete examples. Others respond to the generalities, and a tangent is created.