And if Amazon supported DRM-free epub, this helps their competitors... how?
By letting Amazon sell their ebooks to Nook customers? To Sony and Kobo owners?
From their easier to use website, with better customer service, better catalog and better promotions and pricing?
The only thing keeping Amazon's competitors afloat at this point is their proprietary format. By now, DRM-free epub is just a way to give Amazon another 10-20% market share.
Those bookstore owners were sold a bill of goods by some ambulance chasers...
BTW: "Open Source DRM"? Really? Good way to help Alf and company.