On the Robart’s bizarre T-card policy

UofT’s Robarts has a T-card policy that I totally don’t understand. And I’m not just saying this as a non-UofT student; I’m saying this is actually a hassle even for UofT students. So you need a T-card to enter the stacks: In other words, if you are a student who’s studying at a different university, and you found out that you need to take a quick look at a book that Robarts has to write your paper (because your own university’s library happens to not have that book), you can’t just go to the stacks to look at it and then put it back. However, you can request an interlibrary loan. So instead of keeping the book at Robarts, which guarantees the book to be available to UofT students, the T-card policy forces students at other universities to take the book out of UofT for an indeterminate amount of time (obviously not going to return it early since it’s so much hassle to take it out), virtually guaranteeing that book to become unavailable to UofT students for a needless amount of time. How is that benefitting UofT students? If someone at Robarts could give a coherent explanation of the T-card policy’s logic I think UofT students will be eternally grateful.