The problem is not with the GPL. The GPL is just as enforceable as any other proprietary license. The difference is that these amateur projects often don't have the resources to fight infringement.
I was addressing what seems to be an unfair criticism of the GPL, and not claiming that the license would help. In fact your comment reinforces the point - even a proprietary license wouldn't help with no legal backing.
You have a legal leg to stand on that some lawyer might potentially fight for you, that's still better than just giving up and surrendering your weapons.
