You could say much the same about learning how to setup X stack on Linux vs just using a service like Heroku.
Most developers probably shouldn't be messing with Docker. If they aren't directly creating value for someone, then their efforts are probably best directed elsewhere. There is value to yourself for learning and scratching your own itch, but that effort needs to be treated like a side project. It doesn't cross over into your real work.
Docker is low level plumbing on which more "user friendly" workflows are being built. These workflows are what developers should be using. Docker is still young, so there is still a lot more attention on the plumbing than there is in any tools which have been built on top of it. That will change as the ecosystem develops.
But this is a common developer problem. Sometimes developers will spend time doing anything other than what they need to be doing to actually ship things. We don't get paid to write code, we get paid to deliver on things with the greatest impact on that bottom line.
Most developers probably shouldn't be messing with Docker. If they aren't directly creating value for someone, then their efforts are probably best directed elsewhere. There is value to yourself for learning and scratching your own itch, but that effort needs to be treated like a side project. It doesn't cross over into your real work.
Docker is low level plumbing on which more "user friendly" workflows are being built. These workflows are what developers should be using. Docker is still young, so there is still a lot more attention on the plumbing than there is in any tools which have been built on top of it. That will change as the ecosystem develops.
But this is a common developer problem. Sometimes developers will spend time doing anything other than what they need to be doing to actually ship things. We don't get paid to write code, we get paid to deliver on things with the greatest impact on that bottom line.