Everyone has their own opinion. Mine, I think it's dumb to block reply for sale thread. Sometime we want to ask questions to the seller. Sure you could pm them but if it's posted on the thread them everyone who has the same question and want to know see the answer. So they wouldn't need to pm the seller. And the seller doesn't get 100 message about the same question.
I will respectfully submit to you that perhaps you are missing the point. Those are good points you make, But...because of the nature of the forum, anytime you make a comment or a reply it "Bumps" the Ad to the top. This is not fair to those that are following the rules and bumping every seven days.