We had a saying in Xbox that you didn't get to become a Microsoft VP until you'd cost the company a billion dollars with some boneheaded mistake. (Data: The Xbox 360's lack of a pad for its DVD drive, the Kin phone -- which was actually a $2B mistake). I guess someone wants to be promoted.
I agree, it's stupid. But it does not warrant a fine.
That's the good side effect of the fine.
Why? You can still buy non "S" editions where you can change the browser. This is essentially a browser subsidy from MSFT :-)
[1]: https://www.geekwire.com/2016/xbox-360-scratched-discs-why-t...
Not even close to answering the original question, but technically, you can install Firefox for Android on some Chromebooks.
Chrome OS devices run Google’s Chrome browser & nothing else by design.
OK, some of them now run Android apps, so I guess you can install the Android version of Firefox on one or two Chromebooks at the current time, but the rest are definitely Chrome only, unless you switch them to developer mode and install a different OS.