The real problem is that the topics are never g8ven the chance to be resolved before being sent down the memory hole.
I'm gonna level with you here, I've been involved in a handful of these discussions (one of which that went on for ~3 days) that have gotten quite a bit into the discussion. The problem that usually causes things to blow up is one extreme person (for either side, I've seen discussions go up from both ways) who doesn't bother to fully read whatever anyone else says and quickly resorts to just launching attacks at other forumites, thus leading to attention from Toady.
The impression that sometimes Toady is fairly quick on shutting said discussions down comes from the fact that we've had a few of said discussions that started to happen shortly after one was shut down (often with extremists on both sides to force a fast degeneration), meaning we (and Toady) could already see what was going to happen because you had the exact same people starting to discuss the exact same topic with the exact same level of hostility. Ergo, a few of the discussions have been shut down within hours (while several have gone for
much longer).
Net Result: As a person who has been involved in a rather large portion of said discussions on this forum stretching back for several years (and who has "argued" on both sides before), I'd say that Toady has been rather understanding and patient with the topic, and that in the vast majority of cases it's one or two forumites that ruin it for everyone else (and who usually get banned permanently after two-three times of blowing up topics like that, causing the "comments/messages disappear" effect that you are seeing).