When I think of Copyleft licenses, I just think of it as "Use this program as you see fit, but if you share/redistribute it, you may not add any restrictions to it."
I don't understand why there are communities that hate GPL so much. It is such a powerful license that practically guarantees that the program will be free for any who wants it, it just won't allow someone to add restrictions to it.
I've heard arguments against the GPL like: "It's too restrictive!" Only if you want your program to be muddled with any kind of program that doesn't respect freedom. Saying the GPL is too restrictive to developers is like saying the 13th amendment of the US Constitution is too restrictive to slave owners.