PC gaming doesn't need more fragmentation. A low level API is a good idea, but it needs to standardized and controlled by a third party. Devs may want low level access to hardware, but they don't want to support multiple rendering paths in order to reach the most customers. AMD claiming this is open is not quite true, Nvidia and Intel will never use this as long as AMD controls the API.
If AMD succeeds with this, it will lead to the demise of competing technologies, and ultimately hurt consumers.