In watching a dual on tv recently, I believe it was Beldam, but I can't remember for sure, the color analyst lamented the lack of D1 quality kids coming out of Oklahoma. His reasoning was somewhat related to what you just said. He said that due to a low wages for teachers/coaches in the state they were lacking quality coaches at the high school level. While the reasoning might be different the results would be the same if we take our kids out of the hands of our high school coaches.
I believe the primary reason we surpass all of our neighboring states is solely because of the quality of our high school coaching.