What would the possible benefit of restricting editing time be?
I really don't care either way, but I know in the past on SBS and other forums I've been part of. You'll have someone post a lot of good info and then for whatever reason decide to leave and just remove it. Then the flow of the thread is totally trashed and the info is gone.
I've even seen where you have a good conversation going and then someone get pissed say a lot of stuff they don't mean, then go back and change it, yet you have several replies with quotes that have the information in there. So in my mind if you post it, you should be willing to live with what you posted.
That is just a few reasons I could come up with. Now granted you may disagree and that is fine.
By the same token I can see where posting information and then wanting to add to it or even change it because the info isn't accurate. But other than that I see no reason to need to be able to edit beyond a certain period of time.
Again like I said I can see it from both sides.