This feature was recommended to me by people in the industry. They took the view that if you're going to grant credit for a much longer period of time, then the question of protecting you and ensuring you are covered becomes quite a bit more complex. There had to be some limit. That limit may be viewed as arbitrary, but the idea is that there has to be some way to put a fence around these claims, so to speak.
On June 1st, 2016. See this statement in context.