No antifeatures / downgrades. I am aware that this is a fuzzy concept. However, a few specifics:
* Think very hard before adding things to make sure that they actually need to be in the core browser. Looking at you, FF Hello.
* Don't baby the user. Everything should be configurable. And existing options should not be changed on upgrades. And general solutions are (always) better than centralized services. Looking at you, Firefox "You cannot install unsigned extensions, period".
* Don't introduce "features" that hurt the end user. Looking at you, Pocket "you now are bound by the terms of Pocket's user agreement when you run FF".
* Don't try to do cat-and-mouse games. Looking at you, Firefox "we must try to prevent malware on the user's computer from taking over FF".
* Don't assume that everyone has the newest and best computer. Looking at you, Firefox "electrolysis tripling memory usage is fine, right?".
* Don't couple security updates with anything else. Looking at you, Firefox "you must downgrade to australis or else your browser will be unsecure aah!".
Sorry, but I'm going to call this arbitrary FF hate.
With the exception of the Pocket and Hello arguments, Chrome has all of these problems. Electrolysis, the malware stuff, etc... all comes from Chrome stuff!
It's not arbitrary FF hate. It's frustration that the browser that I used because it didn't have any of these problems has decided to emulate the antifeatures of a browser that I don't use because it does have these problems.
As you said, it all comes from Chrome. Well... Guess why I don't use Chrome. And guess why I've switched away from mainline FF.
It's bloat. Memory use, startup time, attack surface, terms of use (although this is more with Pocket than Hello), number of things that need to be configured on install, etc.
I have no problem with Hello as a concept. I have every problem with it being part of the core browser as opposed to being an addon.
* Think very hard before adding things to make sure that they actually need to be in the core browser. Looking at you, FF Hello.
* Don't baby the user. Everything should be configurable. And existing options should not be changed on upgrades. And general solutions are (always) better than centralized services. Looking at you, Firefox "You cannot install unsigned extensions, period".
* Don't introduce "features" that hurt the end user. Looking at you, Pocket "you now are bound by the terms of Pocket's user agreement when you run FF".
* Don't try to do cat-and-mouse games. Looking at you, Firefox "we must try to prevent malware on the user's computer from taking over FF".
* Don't assume that everyone has the newest and best computer. Looking at you, Firefox "electrolysis tripling memory usage is fine, right?".
* Don't couple security updates with anything else. Looking at you, Firefox "you must downgrade to australis or else your browser will be unsecure aah!".