Moderation is the only reliable way of preventing undesirable posts. Unfortunately, undesirable is at the discretion of CA - which, while I don't like it, it is their prerogative to impose.
What I really find detrimental is that the delay introduced (usually minutes but sometimes appears to be hours) can get in the way of an active "conversation".
Now, I don't know what others see but the flow of conversation and implication of the "your post is being moderated" is that until moderated, no one sees it.
-Garin