The trouble is, there are certain core journals that are really needed and many crap journals. Subscriptions come in packages, i.e. a library can't choose to keep Cell and get rid of Bioorganic and Medicinal Chemistry, they can only cancel Elsevier altogether. That's why the campaign failed last time, there wasn't a critical mass ready to unsubscribe from everything to convince the publishers to get their act together. Maybe this time, with Scihub, things improve.

I predict that Elsevier & friends are going to use their influence on Congress to implement internet filtering at universities to keep Scihub out. It worked for the music/film industry.