JonTex, most of the time, moderators enforce the "rules" of what can be equated to a private golf or any other club. By using this site, you are legally using a private service, i.e. company forums, which is owned by a private company. So while "here" you are on "private property" and subject to enforcement by the moderators, i.e. the club owners to either be banned, deleted, etc. by not following those rules. Sure you can get into the argument that your own country has certain rights, but the moderators are legally able to restrict you from this site if they deem it necessary.
So in essence, this gives the moderators to enforce the forum rules as they see fit. If they feel a post is going to start a flame war, then the moderator has to step in and "punish" you by giving you a warning. It flags you, i.e. gives the moderators more ammunition to tell the community manager, "Hey this person is causing trouble, ban him" and so on.