As I said, because right now it doesn't actually do anything. So why are we making it harder for student athletes for no gain. It's a charade.
If you want to make it stricter, then you're actually harming students who transfer, not just inconveniencing. There are many student athletes who are forced to transfer for very legitimate reasons. So then you're really valuing the game over the quality of life of people. I find that morally wrong, but we may disagree. You could add waivers and exceptions. Depending on how it's executed, I could even be okay with that system, but as we've seen finding the balance between tough to deceive/exploit and working as intended to prevent unjust injury is extremely difficult.