You are right that if you are creating a custom tool you can create that restriction easily.

But if you are creating a learning management system where administrators can configure it a million different ways and the university lawyers want to make sure that administrators don't set it up the wrong way, it makes sense to have that safeguard.

You are looking at the wrong level here. This isn't a software coding issue around technology. This is a policy compliance issue around people. When you create tools you have to consider the possibility of those tools being misused by an employee and mitigate those risks when possible.