I myself borrowed an old book (which I already owned, but I wanted to compare differences among versions), turned a few pages, but then got distracted and didn't open it again (the virtual loan expired).
I think it's a shame that people are trying to crucify an exemplary organization for doing a charitable act (no good deed goes unpunished, and all that).
And, to be quite honest... Most of the books are at least 20 years old... So it's not like they were distributing best sellers that were actively being sold.
I think it's a situation where publishers "are being forced" to be litigious, because they have an obligation to their shareholders to always take the option that yields more money; the Internet Archive just happened to leave themselves open to being a target, so they _have_ to do it.
This reminds me a bit of Commander Chris Hadfield's cover of Space Oddity, and if I recall correctly, that David Bowie didn't own the rights to his own song and thus was unable to approve or deny an extension for Cmdr Hadfield's video on YouTube (and the controversy of the takedown).