What this guy has put forth is his personal philosophy. My guess is that he came to believe in the primacy of biomechanics because he has had a personal breakthrough in his own running while focusing on his biomechanics. He is likely blowing out of all proportion an n=1, or case, study, all the more flawed because one makes even more erroneous assumptions when studying oneself. He is also a physical therapist, and when one is a hammer, every problem becomes a nail (or something like that). And, most importantly, perhaps, he posted this in a blog, and then on letsrun, rather than in a scientific journal. He is looking for attention. Probably the best course of action is to ignore him. But I can't.
I think his main problem is that he is confusing necessary with sufficient. Perhaps an efficient running style is a necessary component of running prowess, but it is certainly far from sufficient, and, indeed, may be one of the less important and less difficult to achieve of the necessary factors. All one needs to do is study the myriad running forms/styles of elite runners, all of whom produce very similar performances, to see that biomechanics/form is not the differentiating factor between good and great and the best. The biggest problem, however, is with the definition of "good" biomechanics and form. How do we define good? Good biomechanics must lead to fast performances, so what we now define as good is a tautology: she who is fast must by definition have good mechanics, which leads to the result that she is fast. "Pretty" form does not equal "good" form. Fast equals fast. As a physical therapist, he is probably also making the mistake of the availability heuristic. He sees runners who have broken down, he is a hammer and therefore sees their breakdowns as nails (or biomechanics) and then tries to fix them. If they are fixed, he assumes that it was in correcting their biomechanics that they were fixed. But time, also, heals all wounds.
Finally, I think I take particular offense at his use of the word "embarassing" to describe our nation's talented elite runners and their biomechanical or form idiosyncrasies. My own physical therapist, who sees many elite and Olympic distance runners, tells me that she has yet to see an elite female distance runner without some degree of lumbar lordosis. She believes that, while predisposing the runner to injury, on the one hand, this may paradoxically provide the runner with some degree of speed ADVANTAGE. It is possible that a certain type of biomechanical "mutation" can be both a blessing and a curse. Tran likes to use analogies. Think of the sickle cell anemia allele. One of them makes you immune to malaria--a good thing. Two of them and you have sickle cell anemia and can bleed out--a bad thing.
No one aspect of running can be the answer to our submission to the East Africans in the running realm. I would argue that the largest factor is culture. Ours lacks patience and steady, quiet determination. We want answers now! (Like the catch-all biomechanics argument that Tran favors.) The East Africans just keep working.