The AACS-LA are a different organization than the MPAA. There are several companies that make up the foundation of the AACS-LA, but only three are movie studios, or have movie studios as part of their organization. Those are Disney, Warner Brothers and Sony. The other founding members are Intel, Microsoft, Toshiba, and Panasonic. So you see, their interest is in the protection of the HD content on current and future Blu-ray discs, and distribution of HD content through other means, which they also license.
DVD-video is not in their purview, though some of their member companies are still protective of the older format. It was Sony that went after RipIt4Me.
Macrovision shut down DVDDecrypter. But Macrovision is now Rovi, and they no longer seem interested in copy protection.