This is a legitimate question. They are a special class of organization and have all kinds of policies to work to. A private company can do what they want.
Somebody somewhere has presumably said "we want to know exactly how many people use it"
Lower down they've said "we need more people signed in"
Then lower down that they've decreed "if we force people to sign in, we'll increase the numbers signing in, even if we reduce the total users using the system"
The problem is the policies.