You know what? You're correct: GPL suits have been copyright suits - but only because the terms of the LICENSE have been violated. Apparently the SFLC (main GPL litigator) hasn't done any of their suits under contract law. Perhaps the overly strict (a.k.a. "draconian") copyright regime we suffer under allows them to more easily win, or at least threaten for more damages.
However, GPL is a license, and it does waive some of the "rights" that usually get claimed, as long as you observe the terms of the license. In that respect, it's identical to EULA's.
But the GPL doesn't do the "it's mine, all mine, my precious" sort of hoarding that the usual licensing does, so I doubt that we'd ever see anyone busting copyright because the GPL is used to create artifical scarities, or jury-rig markets or the other stuff Big Media does with "all right reserved" copyright.
The GPL2 is less restrictive than any EULA I've seen -- it only addresses distribution, and only restricts things that standard "All Rights Reserved" copyright would restrict anyway. It's purely a copyright license, and I respect it for that, even if morons paste it into the "I accept" textarea in their installer-builders.
The AGPL, now that's a EULA. It hits the trifecta of basic wrongheadedness, poor implementation, and total unenforceability. The only thing it's missing is the admonition against using it in a Nuclear facility or exporting it to Libya.
However, GPL is a license, and it does waive some of the "rights" that usually get claimed, as long as you observe the terms of the license. In that respect, it's identical to EULA's.
But the GPL doesn't do the "it's mine, all mine, my precious" sort of hoarding that the usual licensing does, so I doubt that we'd ever see anyone busting copyright because the GPL is used to create artifical scarities, or jury-rig markets or the other stuff Big Media does with "all right reserved" copyright.