Great thread. Great insights.
Makes me think the corollary argument might be:
"Why aren't the Kenyans any good at baseball ? Why are the Carribbean nations always beating Africans out for the top dollar baseball contracts."
The East African nations have maybe soccer, and running, and not much else in the way of diversions.
I think it truly is cultural.
* school busses, or running 10k am / 10 k pm (would you send your kids thru the gauntlet of todays freaks & molesters to run to school ? no way!)
* high fructose corn syrup, or farm fresh diet
* running running & more running, or soccer t-ball girl scouts boy scouts hockey football basketball
* running & farming on foot all day, or playstation, tv & internet
As a runner I've learned from my own experience that it's the little things, and they all add up. The above "little things" are not so minor.
Lastly, if the sub-2:08 marathoners are training their recovery runs and easy days at race pace + nearly FOUR MINUTES per mile, I am going WAAAY too fast on mine. Woopsie. Well, also, I'm doing a fraction of the mileage volume too, so that is a factor, but I have tried to slow down on those runs this year and I think I will do so even more. I'm within 60-90 seconds.