Yes, I love the space of regular libraries but too much of the space is devoted to old books. I like the romance and the smell, but if I can't find a place to sit what good is that?
Part of the reason libraries are quiet is you have fewer people and a lot of sound absorbing materials (that also happen to hold really important information for the right people). Removing books and replacing them with more seats will just make it an open office.
A library is supposed to house knowledge and make it accessible, not primarily to give everyone a study spot. You can always check out a library book and take it somewhere with more seats.
Libraries have two problems - guessing what books their patrons need and should be acquired, and guessing what books they have that their patrons no longer need.
The second process, "weeding the collection", at least can be informed by circulation data as to whether a book has been loaned in the last several years, as well as other criteria such as rarity, historical importance, being part of a special collection, availability from network libraries, and conditions under which it may have been gifted to the library.
