I'm really sorry it's felt like a slog for your team. We've learned a lot from the transition from 1.x -> 2.0, and definitely didn't get everything right. That said, we think we can refine the 2.x -> 3.0 transition to make it much smoother based on what we've learned.
Given how fast the frontend ecosystem is moving, we've tried to strike the right balance between delivering new features and taking care to ensure that we don't leave the existing ecosystem of apps behind.
I think you'll agree that if we did nothing, our community would slowly die off as people moved to competing libraries and frameworks that made them more productive. So total stability would feel good in the short term, but long term, having to do a wholesale rewrite of your app because the framework stagnated would be much more painful, right? (You can approximate this effect by locking yourself into an older version of Ember, which sucks! People rightfully want the new features.)
The goal of Ember's additive-only strategy is to deprecate features, rather than remove them. This is more work for the maintainers, but we think it's worth it because users can "refactor towards the future" at their own pace, amortized over the year and a half between major releases. Development teams have a natural ebb and flow, and that amortization of deprecations over the year means you can use lulls/downtimes to refactor the deprecations out when it's most convenient to you.
We made a mistake and rushed in a bunch of deprecations in 1.13 because it was our last chance to remove features for the next year or so. In retrospect, we got overzealous, and for that I am sincerely sorry. Users like you rightfully felt overwhelmed, and that is something the entire system is designed to avoid.
If there's a bright side, it's that your app should continue to work as you upgrade, and when you're ready to make the jump, you can upgrade to Ember 1.13 and refactor away all of the deprecations. Once that's done (whenever you decide to do it), you will be able to upgrade to the latest version of Ember 2.x, because Ember's SemVer guarantees means that a deprecation-free 1.13 app is compatible with any 2.x version (2.7, for example).
Sorry again that it's been a slog for you. Once you're through it though, we hope you enjoy all the new features, and we certainly hope the simplifications we've made to the framework over the last year make it easier for new developers to join your team and get productive.
Given how fast the frontend ecosystem is moving, we've tried to strike the right balance between delivering new features and taking care to ensure that we don't leave the existing ecosystem of apps behind.
I think you'll agree that if we did nothing, our community would slowly die off as people moved to competing libraries and frameworks that made them more productive. So total stability would feel good in the short term, but long term, having to do a wholesale rewrite of your app because the framework stagnated would be much more painful, right? (You can approximate this effect by locking yourself into an older version of Ember, which sucks! People rightfully want the new features.)
The goal of Ember's additive-only strategy is to deprecate features, rather than remove them. This is more work for the maintainers, but we think it's worth it because users can "refactor towards the future" at their own pace, amortized over the year and a half between major releases. Development teams have a natural ebb and flow, and that amortization of deprecations over the year means you can use lulls/downtimes to refactor the deprecations out when it's most convenient to you.
We made a mistake and rushed in a bunch of deprecations in 1.13 because it was our last chance to remove features for the next year or so. In retrospect, we got overzealous, and for that I am sincerely sorry. Users like you rightfully felt overwhelmed, and that is something the entire system is designed to avoid.
If there's a bright side, it's that your app should continue to work as you upgrade, and when you're ready to make the jump, you can upgrade to Ember 1.13 and refactor away all of the deprecations. Once that's done (whenever you decide to do it), you will be able to upgrade to the latest version of Ember 2.x, because Ember's SemVer guarantees means that a deprecation-free 1.13 app is compatible with any 2.x version (2.7, for example).
Sorry again that it's been a slog for you. Once you're through it though, we hope you enjoy all the new features, and we certainly hope the simplifications we've made to the framework over the last year make it easier for new developers to join your team and get productive.