Copyright is most definitely not a good force. Whenever the government intervenes to prevent voluntary transactions among individuals, it destroys more value than it creates. Copyright falls under that category.

So be it; if we got rid of copyright and lost copyleft in the process, I'd consider that a net win. The Free Software Foundation has said on several occasions that they feel the same way.

GPL was really just an attempt to use copyright against itself anyway.

I think the key thing to note is that it would be less necessary, since there would be no legal means to prevent you taking apart a compiled binary, working out how to improve it, and sharing those improvements.