While I’m glad they are speaking up against it, I don’t believe that it will change anything. If Google decides to implement it, it will just end up exactly like it did with WC3 EME, as summarized in this the 2014 article from if I’m not mistaken a Mozilla dev:

I know of people recommending Chrome (not Chromium) because it has Flash Player natively incorporated, so you no longer have to install it separately.

This serves to prove that the majority of users doesn’t know about either the technical or ethical differences in the software they are using.You may also think of the pirated software the are using,but this is a different matter. Ignoring this marketshare goes against Mozilla’s idea of a web available to everyone, not to mention that Firefox is no longer the most used browser as it used to be a a few years ago and it is therefore forced to comply with this kind of requests.