Unless you give me $50.00, you cannot have this software.
Unless you give me $50.00, you cannot have this book.
See the similarity?
Why shouldn't the information in the book be open and free, and indexable by the search engines?
Why hold a gun to my head before I can access your book? Books are like closed source software. There is closed source software available "for free"
At least with GoogleBooks? tool we can peak into the book before buying it.
At the PublicLibrary? you can borrow copies of the book at no charge, but not all books are available in the library. Many (most?) libraries participate in inter-library loan programs. If a book you want is not at your library, they can often get it for you.
If you wait long enough you can get interesting books in second hand bookshops. This is caused by people selling on books which they no longer need.
SecondHandBooks? ( is there a source for SecondHandSoftware? - I don't think so - If so: I want to know )