It's really a problem in general, there is no way to make an extension that customizes browser behavior itself (rather than page behavior), since WebExtensions can't do that.
Quitting Firefox and then starting again and restoring all tabs fits well with easy to undo.
Same with the backspace key activating the back button. Using these keystrokes for these purposes should be considered harmful.
Ctrl-Q is so harmful that I've long fantasized about hacking whatever driver in the kernel that controls the keyboard and having it ignore whatever signal the keyboard sends out whenever you press Ctrl-Q and not even pass it on to userspace.
tell application "Firefox"
set buttonStr to "Ooops"
set errMsg to "Close with ?-Q disabled. Use the menu."
display dialog errMsg buttons {buttonStr} cancel button buttonStr default button buttonStr with icon stop giving up after 5
end tell
So confirmation for Ctrl+Q is a must, there is no question about it. And if you don't want it - they can make an option that can turn it off.
Not only that, but it can take a significant amount of time to restart the browser and reload the tabs you had open.
So just in terms of time wasted, accidentally quitting the browser and having to restart it is awful and painful compared to just canceling the quit.
HN doesn't use those warnings. This reply was first written, then I quit and restored, and now I'll hit Send.
Yes, they probably should show a warning, but browsers developers know very well they can't rely on websites to always follow the best practices.
Say I write a user.js file with a few options. I can't have the typical dotfile model, where removing options from this file will lead to defaults on the next run. I need to unset them. Explicitly.
Thus, using a dot file to set up Firefox (user.js) is incredibly clunky and people don't use this much.
There exist good cases for instant persistence, like switching themes when you want to see the effect immediately before you decide.
Other than that it's really nice to be able to cancel everything when you realize you've messed up.
It's not binary. Both solutions can coexist as long as we choose the right tool for the job.
I tried setting this (and only this) to true, but ctrl+q still quits without a prompt.
That option literally prevents the prompt from happening.
Reported: 9 years ago(!).