I have closed a lot of the old threads as new people would come along and post a question in a thread that was months, or in some cases over a year old and then they got upset when no one answered them as the person who started the thread or posted last was no longer around.
I picked the two month average (although I usually leave the recipe ones open longer) as I did thread cleanup last year on my Christmas vacation and it took me 6 hours to do it!!!!
I don't want to go through that again, especially with the 3 forums that I moderate.
Basically it is just for clean up and forum maintenance and not to do with anything bad or controversial.
If you want to readjust a recipe then you can either repost it as a new post or just send me a pm and I will re-open the thread temporarily to give you an opportunity to make the changes. You can always pm the person who posted the recipe and ask them questions.
I also amalgamated a lot of recipes on the same topic (i.e. cheesecakes, pies, lasagne) into one common thread and closed them hoping that members would post some brand new ones in the recipe forum -. (That's a hint for everyone to post some by the way . . .