The reason why a Journal starter can't be a moderator of his own journal is simple: It's a conflict of interest. You can't have a journal that reflects your own beliefs but then be expected to objectively moderate the comments and criticisms submitted by others about you at the same time. It's like watching a court case where the plantiff tells his story, the defendent then tells his, and then the plantiff walks up to the bench and puts on his black robe and sits down in the Judge's seat to rule on the case. The mere notion of one side being able to have control over the other makes the whole event pointless.