I think it should!
As many of should know, if a poster posts a reply to an old "dead" thead an admin will frown them for "reviving" a thread and then close the topic.
However there are times when inportant things need to be said on that topic - the poster may have never seen that topic and then one day s/he decides to look threw some old topics, sees something in the thread that needs to be replied to for some reason, be it personal or the answer that is needed.
Other forums I am/have been a member of actualy don't have this rule.
However a slight negative side is that when a topic reaches 30 pages (That actually happend once) it can be quite tough to find where you are.
I am in no authority but hopfuly the votes will cause the admins to reach a descision(sp?)