Interesting question, to which many people can offer opinions, but the answer can never be known with certainty. Is the US college system worse than the system that Kenyan and Ethiopian runners develop in? Or do they do better because of growing up with fewer distractions, altitude, different diet, more empasis on running in their culture, or something else? People tend to point to the most successful way of doing anything and say "that's the best" but for all we know another way would be better, it just hasn't been used by as talented a runner (or swimmer, teacher, or whatever it is you're trying to measure).
In the scietific world you would try to develop the closest thing to a counterfactual, where you have 2 identical groups with the ONLY difference being the training system (no differences in culture, climate, diet, background, or anything else), and then measure results after a certain period. Since this is impossible to do (maybe one group has more naturally talented runners, even though at the time of randomization they had equal times to the other group, or one group had better weather to train in, or one group didn't get along with the coach and didn't follow the exact system, etc.) we'll never know the answer.
For people that say "look at Webb, he's done so well out of the college system"- perhaps he would have done just as well, or better in it.
I tend to in general think there is no "right" way to train, there are a bunch of ways that have shown to improve people's performances over time. Some may work better for certain people. Hopefully everyone finds a system that they enjoy being in, and that seems to help them improve, but I would remember that one mans dream system may intolerable for someone else.