They are under no obligation to enforce the copyright and refuse a liberal license.
Anyway, archiving is exempted from copyright.
http://www.copyrightuser.org/educate/intermediaries/archives...
Archiving under some strict prohibitions are possible, but it's sort of a narrow window which is difficult for e.g. abandoned commercial works.
In the same vein, they are under no obligation to _not_ give it away from free. Their actions are purely a choice, free from obligation. That said, lack of obligation does not act as a shield from criticism. Quite the opposite.
Personally, I might blame the descendants of Disney the most if they had significant voting shares in Disney Corp, but as to the rest I doubt played a key role in the expanding copyright to the degree it has today.