Sorry, I wasn't clear (and have edited the post), I absolutely do believe that usability is important, and to be honest I feel like it's the main problem with graphics APIs (at least for my skill level).

Where I'm at now is that Vulkan is great because it's removed so many of the hard-coded assumptions that were previously hidden in the driver layer, allowing much greater CPU and GPU utilisation and performance when you need it (if you can get past the ugly APIs).

Where the usability stuff comes in is that it allows for the creation of alternative, higher-level shader-reflection setups that work brilliantly for simple use cases, all in user-space, which can open up shader programming for creative coders and a broader spectrum of developers. The lower-level APIs are then still accessible to those who absolutely need those performance levers.