Its the fact that a coach who recruits dominately Americans has to work harder to get those Americans to work harder...you recruit a Kenyan, you just got to give them good and smart training and they'll motivate themselves to get the job done. So coaches without Kenyan athletes look for a cop out and come up with stupid criticisms even though that a 4-minute miler from Kenya is exactly the same as a 4-minute miler from the U.S. Most Kenyans recruited are equally fast (at best) than our top high school graduates. In fact I learned in my 4-years in college that most Kenyans recruited are slightly slower and in fact are less likely to run well their first year due to adjustments of lifestyle. But in the long run, they out work the American athletes (not all but most) and turn out to run faster. And the American athletes who can run and beat the Kenyans, guess what, also work hard just like them also!
The point I'm making, there is no difference, just people looking for a cop out.