Because the "proper context" in this case is what the publishers are filing the lawsuit about. It doesn't matter whether you agree or disagree with the publishers. To the publishers, unlimited simultaneous users is the same as unlimited copies. With public libraries, they paid for limited simultaneous checkouts of digital ebooks which is limited copies and that was acceptable by publishers. In contrast, IA did not pay publishers a license to make copyrighted works available to unlimited users.

The publishers didn't file lawsuits against public libraries; they filed it against IA. In your own words (since you don't object to the word "unlimited" and you thought my summary was unfair), what exactly did IA do that the publishers are filing lawsuit about?