While he certainly makes a good point, it's basically the "apple effect." Someone mainstream takes an idea that was created years ago, translates it well to the public and is viewed as visionary. I appreciate his columns, but for their intangible nature. For instance, I love his Mad Men power rankings and his goofy partitioning when evaluating NFL or NBA talent.
If he had truly attempted to make sense of the red zone, he would have tried to determine if there is any validity in the idea by comparing the larger value of EP once you reach the 20 against the likelihood a team reaching that yard line on any given drive and then doing the same for other yard lines. If the magical yard line isn't the 20, then it surely must exist somewhere else and serve as a benchmark for the ability to close out drives with a short field. If there isn't a magical yard line, then I guess he is correct, but the last line in the following link sums it up pretty well.
Anybody who has a real problem with [the red zone] -- and I'm not sure the writers of this piece even fall in that category -- is just being pedantic, and holding sportswriting to an absurd standard of strict intellectual rigor.
This one is in response and is basically what I am saying. Nice try Bill Simmons, please be real.