I'd argue frameworks are their own language built on top of another, but this is all semantics.
As far as learning curves, I'm taking the GP's word on Ember's difficulty to learn, but generally as mentioned below, I don't think you can truly learn a framework that quickly.
Convention, best practices, etc take time. For example, someone that learns AngularJS in a day could end up using $scope, a practice abandoned for many reasons for alternate methods. So does standardizing devs and dev teams on the same practices. A lot of these things often take mistakes to truly understand, or someone who has seen a lot of them within close proximity. The way people write code for each of these programs evolved though those exact mistakes. A framework can constrain, but there are still plenty of ways to mess up at a high level.
As far as learning curves, I'm taking the GP's word on Ember's difficulty to learn, but generally as mentioned below, I don't think you can truly learn a framework that quickly.
Convention, best practices, etc take time. For example, someone that learns AngularJS in a day could end up using $scope, a practice abandoned for many reasons for alternate methods. So does standardizing devs and dev teams on the same practices. A lot of these things often take mistakes to truly understand, or someone who has seen a lot of them within close proximity. The way people write code for each of these programs evolved though those exact mistakes. A framework can constrain, but there are still plenty of ways to mess up at a high level.