Herbert- I still am not sure, but I have my theories.
First of all I ran LSE varsity in the late 90s. While I did not know it at the time, our training was based heavily on Daniels and Vigil. A lot of Max V02, etc. A lot of our miles were spent at probably too fast of a pace. But we were definitely not doing speed stuff, you can look to our track results as evidence of that. Good but not outstanding.
That being said on the distance side, in XC at least, there are two main causes in my opinion.
One is lack of coaching. Many coaches in Nebraska don't have a clue as to how to train for distance events. I am still learning myself, but have my philosophy down pretty well.
Two is terrain. As you know our state course is a tough one. I look at places like NY or CO or IL where the state XC courses are incredibly fast and we just don't train for that kind of course. I am sure the top runners from other states would run fast, but I am not convinced you would see many sub 15s at Kearney like you do elsewhere. So we train for the state meet, which means training toughness, which like Brian said does not necessarily mean being faster.
This is one of the issues I would like to research more. That is see the history of times in Nebraska across all classes and compare some averages to other states. It is also an issue to present to our coaches association and see what they think and if we can collectively improve distance running in our state.
I fail to see how this issue involves Ben Nelson. Unless he has some 4k or 5k training advice.