Terrible for so many reasons. Chrome did it first, and now Firefox wants to follow in its footsteps (as usual - Google sets web standards now, and Mozilla rolls over and says we better do it too). There are so many use-cases where auto play sound and video are legit and valid. Yes, some sites and platforms abuse this, but a lot don't. We're being punished for bad apples again, and that's not the way to run society. Common sense is gone.
This should have been implemented as a user preference that by default isn't enabled. Instead, they just force their will by default on everyone when a standard existed allowing for the auto play of audio and video. Great way to break a lot of applications. Especially for the deaf and blind (when it comes to voice to text and text to voice). Now they have to "interact" with the page before the media will play. Lots of games and other things will be broken from these changes. Great job guys! Let's continue to break things that used to work. Great way to develop applications. This used to work, but now doesn't. Thanks Google for your BS. Read how many people developers were unhappy about Google's changes here: