From my mathematics training, I tend to speculate about changing rules, and what outcomes are likely.

This weekend, I wondered what would happen if the "recent backpay" was changed to "oldest backpay."

One effect is that the very old backpay would be paid out.  In the current system, there is some doubt whether it will ever be paid.
Another effect is that new miners would see a drop in their revenue, because initially they would not receive any backpay.
Possibly a blended system, 50% recent and 50% oldest would balance these two concerns.

I assume wizkid & Luke evaluated this question in the past.  I wonder what their reasoning was.