With the internet, online books you can download or purchase, online encyclopedias...who needs to go to a library?
“Well, let me tell you something, funny boy. Y'know that little stamp, the one that says ‘New York Public Library’? Well that may not mean anything to you, but that means a lot to me. One whole hell of a lot. Sure, go ahead, laugh if you want to. I've seen your type before: Flashy, making the scene, flouting convention. Yeah, I know what you're thinking. What's this guy making such a big stink about old library books? Well, let me give you a hint, junior. Maybe we can live without libraries, people like you and me. Maybe. Sure, we're too old to change the world, but what about that kid, sitting down, opening a book, right now, in a branch at the local library and finding drawings of pee-pees and wee-wees on the Cat in the Hat and the Five Chinese Brothers? Doesn't HE deserve better? Look. If you think this is about overdue fines and missing books, you'd better think again. This is about that kid's right to read a book without getting his mind warped! Or maybe that turns you on, Seinfeld; maybe that's how you get your kicks. You and your good-time buddies. Well I got a flash for ya, joy-boy: Party time is over.”
One MAJOR reason is editing.
An online book, can be chopped up, added/ deleted/redacted on the fly.
a printed bound book is unchangable.
yes you could pull it and put in a “new edition” but much more difficult to do on a lrage scale.