He has a driver's license with his address on it. Did I mention I was not allowed to check out the books he had on hold even though we live at the same address?
I already responded to that part of your comment. Your library card is yours and yours alone. It's not held jointly by all members of your household. Scoff if you want but there are important privacy concerns. Maybe you don't see those concerns because you're thinking "why would my husband care if I check out his John Grisham books for him?" But libraries deal with many circumstances you may not be aware of and are damned if they do and damned if they don't.
Someone like you is upset if not allowed to check out your husband's books. On the other hand, someone else would be understandably upset if they requested books on, say, divorce, abuse or some other touchy subject and the library handed those books to her husband or someone else in her household without her consent. Maybe these were books she was using to research something privately, that she didn't want her husband to know about. The point is, she has a right to expect that books reserved under her card are meant for her alone. That's a reasonable assumption.