FWIW, it's not completely clear this is the correct way of addressing the issue in football.This brings up an interesting point, one that is taken into account in football rankings on various levels. After a certain point, even though baseball is significantly different in this regard than football, the run differential should be capped. Let's say 8 runs, since after that point there tends to be significant lineup/pitching changes (or in the case of pitching - lack of changes) from both teams. I am not sure that would significantly change relative run differential, but I believe it would certainly make sense to have a cap when we look at run differential.
Part of the problem here is that, statistically speaking, some studies show that curb stomping weak opponents is actually a very strong indication of team quality, even greater than beating quality opponents. Basically, close games ride on a few coinflips, but good teams more reliably thump weaker opponents, so you're getting a different sort of information.