Good point, B.G. Having athletes who develop well long-term is part of the mark of a great coach.
With regard to the original post, it's just silly to BELIEVE that you can't win NCAA's from the back. It's been done, and anything that has been done, obviously can be done.
However, it's not silly to SAY that you can't win NCAA's from the back; in the same way that good athletes are "24-hour athletes" who structure their whole lives around getting fast and beating people, good coaches are always looking for a way to get an edge that might help them beat teams. He's not trying to give your little sister pointers about how to coach a team to a national championship; he's trying to win meets.
Any top-flight high school runner is looking at a small group of collegiate programs, two of which are Oregon and Colorado. Both are pretty powerful and pretty diametrical brands; Oregon has built up around it the cult of Prefontaine and Nike, and Wetmore has RWTB. Frontrunning and coming from behind are a big part of those brands.
Lananna knows--and Wetmore knows--that you can win a meet in a million different ways, but by broadcasting that you can't win from behind, Lananna is trying to diminish the Wetmore/Colorado brand. The "At least, I don't think you can," serves to highlight the difference. If he can get more kids to believe that his way is better than Wetmore's way, he can pull in more big-time recruits.
Whenever you're looking at a coach's interview, don't take everything he says at face value; consider what he might be trying to accomplish.