The more threads you have the more resources are required for moderation. If comments were enabled for every single thread on an old enough site they&#x27;d need entire teams just to keep the spammy comments out.<p>When threads are closed you have a lot less moderation work to do to keep the site from being infested with spammy outbound links<p>It&#x27;s unfortunate but the value of the odd one or two people commenting on an old post isn&#x27;t great enough to outweigh the need to easily keep the site spam free for many sites