What you say makes a lot of sense, yes.
The problem is thinking about it as if they are student-athletes. That is what is commonly sold to us, the consumer.
The truth and reality if it is that they are financial assets and every college is a business, often times a state run one.
Ergo, if money is to be made, they will try to make more of it. The lesser time (years) the kids have in school with less time exploiting their name, image, likeness, and athletic prowess then that means the less peak profit they stand to have.