I don't know, but I have a theory why this keeps happening year after year. (when we don't have a kicker who can send it out of the endzone)
We all know we don't have the monster athletes that some schools recruit. Yes, we do have some talented skill players, and our guys play intelligently most of the time. And, I believe our coaches coach them up very well generally.
BUT, on kickoff returns, it is probably more about "mano a mano" than any other time, and we don't win many "mano a mano" battles. Just my theory. Not sure what coaching could do to have guys run faster and be tougher getting off of blocks.