What is the point of the rules on necroposting?

[Bohandas]

Recently I've noticed several active discussion threads get shut down because one of the moderators noticed that there was a 46 day gap in the discussion half a page back. I would like to know why this is. The explanation we had always been given was that if there was a gap that long then there must not have been anything left to say. However several of these had several posts after the offending post, and in at least one case I observed the offending post was from over two months ago and the conversation had continued from that time up until the thread was abruptly closed.

What is the point of this?

[Grey_Wolf_c]

See here

Grey Wolf

[Roland St. Jude]

Sheriff: Indeed. This has been answered repeatedly, including last month:

Sheriff: This question has been answered before in this subforum. Among many other reasons, it prevents people from trying to carry on a conversation with posters who have left (the thread or even the forum); it promotes active discussion that is inviting to new posters and not weighed down by discussion of prior posters who have already abandoned it; it prevents the revival of threads that are old enough to have embedded errors caused by one of the board transitions; it prevents the need for posters to search or view older threads, lessening the use of forum resources.

As with all our Forum Rules, we're aware that there are alternatives, and costs and benefits, but we've chosen this particular policy judgment as best for this forum.