Some believe that a viticultural area's reputation can be diminished and injured if allowed to be used as a brand name without restrictions. Some believe that a producer has the right to call a product by any name as long as it does not conflict with another person's trademark and is not misleading. Some believe a little bit of both. It's pretty common for wineries to use place names, real or imagined, as the brand name and trademark for their product. You know, places like Sonoma Vineyards, Napa Ridge, Stag's Leap, are all brand names that just happen to be place names as well.
Wineries have brand names because they want to build name recognition.
When a regulation operates to restrict the use of a brand name that was used without restrictions, the brand owner gets hurt. ATF regulates label and advertising terms. Despite the lack of authority by ATF to regulate quality , ATF can sure do a great job of regulating the use of words in labeling and advertising. ATF can't regulate quality, but they can establish standards and require that truthful, adequate, and specific information reach the consumer. Anyone can petition for a viticultural area.