I like the general idea, but I imagine WhatIf would prefer knowing exactly how much was going to be given out in credits each season, instead of playing a lottery of sorts with trying to predict the number of .500 teams not in the playoffs. If nothing else, the current system makes the accounting easier.
That said, they have access to enough seasons of data that should be able to predict what they'd have to give out pretty damn well, and this would be a much better way of giving out credits than giving the 4th place team anything.