Also...

> granted by Adobe to individuals and organizations that desire to develop, market, and/or distribute hardware and software that reads and/or writes image files compliant with the DNG Specification.

If I use it for something it's not images because I want to create a DNG file that's a DNG file and a Gameboy ROM at the same time. Or if I'm a security researcher testing non compliant files. Or if I'm not a great developer or haven't had enough time to make my library perfectly compliant with the specification... Will I be sued for breaking the license?

The fatal scenario for a camera vendor would be to transition your customers to DNG over some years, then a dispute arises which causes Adobe to revoke your patent license, and suddenly all your past products are in violation of Adobe's DNG patent.

You not only have to remove DNG-support on those products, but due to warranty-law in many countries have to provide an equivalent feature to the customer (--> develop a converter application again, but this time for products you already closed development for years ago).

Alternative would be to settle with Adobe to spare the cost for all that. So Adobe has all the cards in this game.

Now: Why bother transitioning your customers to DNG...?