This isn't just coach speak. OSU has serious offensive problems. Miller has all the potential in the world, but still needs to improve his accuracy significantly to be consistently good. However, even if he improves his accuracy, OSU still doesn't have a proven outside receiver threat and no established tailback. Furthermore, they lost two future draft picks (Adams and Brewster) off of a pretty poor offensive line.
The defense will keep them winning, but expect no more than 8ish wins and a couple really embarrassing outings.