Needless to say, DRM is a controversial topic and I am clearly against it. I do not blame Mozilla. The non-profit organization responsible for Firefox knew that they could not oppose Chrome, IE, and Safari while being a consumer software provider. I do not even blame Apple, Google, and Microsoft for their decisions, either. This problem is much bigger and it comes down to a total misunderstanding of basic mathematics (albeit at a ridiculously abstract and applied level).
Simply put, piracy figures are meaningless. They are a measure of how many people use content without paying (assuming they are even accurate). You know what is more useful? Sales figures. Piracy figures are measurements, dependent variables, and so is revenue. Measurements cannot influence other measurements. Specifically, measurements cannot influence anything because they are, themselves, the result of influences. That is what "a measure" is.
Implementing DRM is not a measurement, however. It is a controllable action whose influence can be recorded. If you implement DRM and your sales go down, it hurt you. You may notice piracy figures decline. However, you should be too busy to care because you should be spending your time trying to undo the damage you did to your sales! Why are you looking at piracy figures when you're bleeding money?
I have yet to see a DRM implementation that correlated with an increase in sales. I have, however, seen some which correlate to a massive decrease.
The thing is, Netflix might know that and I am pretty sure that some of the web browser companies know that. They do not necessarily want to implement DRM. What they want is content and, surprise, the people who are in charge of the content are definitely not enlightened to that logic. I am not even sure if they realize that the reason why content is pirated before their release dates is because they are not leaked by end users.
But whatever. Technical companies, who want that content available on their products, are stuck finding a way to appease those content companies in a way that damages their users and shrinks their potential market the least. For Mozilla, this means keeping as much open as possible.
Since they do not have existing relationships with Hollywood, Adobe Access will be the actual method of displaying the video. They are clear to note that this only applies to video. They believe their existing relationships in text, images, and games will prevent the disease from spreading. This is basically a plug-in architecture with a sandbox that is open source and as strict as possible.
This sandbox is intended to prevent a security vulnerability from having access to the host system, give a method of controlling the DRM's performance if it hitches, and not allow the DRM to query the machine for authentication. The last part is something they wanted to highlight, because it shows their effort to protect the privacy of their users. They also imply a method for users to opt-out but did not go into specifics.
As an aside, Adobe will support their Access DRM software on Windows, Mac, and Linux. Mozilla is pushing hard for Android and Firefox OS, too. According to Adobe, Access DRM is certified for use with Ultraviolet content.
I accept Mozilla's decision to join everyone else but I am sad that it came to this. I can think of only two reasons for including DRM: for legal (felony) "protection" under the DMCA or to make content companies feel better while they slowly sink their own ships chasing after numbers which have nothing to do with profits or revenue.
Ultimately, though, they made a compromise. That is always how we stumble and fall down slippery slopes. I am disappointed but I cannot suggest a better option.