All right, in principle you are making a copy when loaning it. In reality, one copy goes to the readers hardware, the other copy resides encrypted and unusable on a server somewhere. This process of copying it is inevitable and is a natural part of any computer system. The same yields for music - which also gets copied to your player without anyone screaming Armageddon. There isn't a real difference: copying something when the "original" is encrypted and in a controlled environment isn't really copying.
As for wear and tear - it has already been stated in this thread that books have a very short shelf-life in bookstores. The current system for books is based on a book making back the money invested in the first couple of years, and many books aren't reprinted. The additional sale of books to libraries is in any case minimal.
I am not an American and may of course have misunderstood many things here. If so, please correct me. This is at least how things work here in Norway