>I have not had an extension break since FF7 (now on FF14)
It's been my experience that extensions don't 'break' (i.e. stop working as expected) as much as they self validate against the currently running version of FF and refuse to load unless the developer has flagged it as workable.
Every time a major release comes out, half of my plugins are disabled. Then, I go and download the compatability reporter plugin (which gives you the option to override the version check), and 9 times out of 10, every single plugin works fine.
Also, what did you mean "how Chrome hides everything"? I'll admit the plugin system isnt near as robust, but for web development, I'm in passionate love with the Chrome/ium developer tools.
I believe it was Firefox 12 or 13 that made add-one compatible by default. Except for add-ons with binary parts, I don't think you should find so many turned off with each update now.
Firefox has come a long way and I as a developer I don't like how Chrome hides everything.
It's also super easy in Firefox to turn off automatic updates and only update manually when you are ready (help -> about firefox)