This is a private website. They are allowed to moderate the boards to remove anything they don't deem appropriate. They really don't want you posting links to stores and they do have a right (whether or not you agree) to remove or edit posts that they deem needing it. If their policy is to remove any particular comments about their advertisers, that is how it is.

This isn't the only board pertaining to the topic. You don't HAVE to be here.