krangodance makes some great points about closed threads, and why they shouldn't be closed. I guess I'm on the fence on the subject.
From what I've seen here over the last number of years, threads get closed when the information turns stale. When nothing new is brought to the table for discussion, we generally end up watching a urinating match about some tangent of the original discussion. These, of course, usually end up in a stalemate - in turn leading to more pointless urinating. When real substance is no longer present in the thread, I don't have a problem seeing it shut down.
FWIW - It's Jim's site, and it seems to me that he wants to maintain a certain level of decorum here - and moderates topics accordingly.
Who are we to disagree?