They did that via public domain usage; the OP is making the point that extending it just to "death of author" will allow Disney to continue to do this. Nowadays

They did that via public domain usage; the OP is making the point that extending it just to "death of author" will allow Disney to continue to do this. Nowadays, they surely can just buy the rights to stuff they want, but that's a completely separate issue and not one that copyright law is meant to address.