Actually, even if negative experience was expected, "none yet" could still be the phrase used. Negative experience is experience nonetheless.
Given the fact that you can read the site just fine without registering, the assumption that whoever registers does intend to post at some point in time is not an unreasonable one.
Actually, you can also post without registering. But that doesn't weaken the assumption much, as posting as Anonymous Monk makes one's posting history hard to track and rules out the possibility of forming an online persona. Registering is a prerequisite for both, but so is posting - therefor, it still is a good assumption that registering implies the intention to post.