Another perspective wrote:
Gilmore talks as if Americans don't want to run 200 miles a week. . . . I don't think I'm the only one here who thinks about stretching, nutrition, weights and form for one reason only - in the faint hope that doing those god-awful activities will enable me to do more miles.
Bingo.
And not to be catty, but somebody brought it up in an earlier post: I've seen RoJo's guys compete on a few occasions, and some of them had form that was not so hot. [Full disclosure: some of them looked great, and some from both groups kicked @ss!]
Some of those same awkward guys, I'm told, developed fairly serious injuries. I can easily see that, particularly if (that's a real if--I don't know the details of their training) they have periods of high-mileage, all-slow running. [Further disclosure: that kind of no-variety running made me a permanently-injured ex-runner, so you can see where I'm coming from on this topic.]
I do think that a person will TEND to find his/her best form through mileage--IF the person has some all-around athletic ability (aka whole-body fitness), which is typically developed through a variety of activities, not just running. Lydiard's guys mostly had that, growing up playing a variety of rugged sports in post-WWII New Zealand; a lot of East African kids have that now; a lot of American kids do not.
I've ranted on this before, but: the demise of daily phys ed in American grade schools--and of just going out to play, at recess (remember that?) and after school--means that a lot of American kids, even those gifted with naturally great aerobic engines, do NOT have the kinesthetic sense and balanced, whole-body fitness to develop efficient, injury-free running styles. And so, just as quoted above, they have to take their medicine (form drills, strength work) in order to keep doing the fun stuff: the running itself.
The running is what really makes you better. The other stuff is what lets you keep running.