> 1/ either try and locate all the add-ons that will be broken, get in touch with their developers, be ignored by most of them, start several weeks of negotiation with those who do answer, then eventually, several months after my code is ready, land the change, and
notice that Chrome has landed that same change a few months ago(emphasis mine)
And responding to that emphasis: so what?! People who use Firefox instead of Chrome do so for a reason! You're failing in two ways: 1) "breaking the user experience of millions of users for no understandable reason," and 2) turning Firefox into Chrome.
If Firefox users wanted Chrome, they would already be using Chrome. They don't want Chrome, they just want Firefox to continue being Firefox, to keep working without breaking their add-ons that make their browser theirs!
Why is this so hard for Mozilla to understand?
The day Firefox stops supporting XUL extensions is the day I stop using Firefox. I've been using Firefox since it was Phoenix. I already have Chrome installed--I'm not using it, and there are reasons for that. You should meditate on this.
Mozilla is slowly committing suicide. It's painful to watch, because it doesn't have to be. One of the great forces in the Internet's history is not going to be around in a few years. Firefox will live on, because of the MPL. But what a shame to destroy the organization that brought it into being. Such a waste.
Oh well. If the Internet has taught us anything, it's taught us that, when it comes to software, developers are fungible. The phoenix will rise again.