"They already do this by letting users install Flash -- in fact, they make it particularly easy to do so, patent-encumbered though it is. And as I've pointed out before, they use Flash to play h.264 video anyway. The difference with <video> is that Mozilla is actively forbidding users from passing that supposed burden onto the operating system vendor, who in the case of Windows and Mac OS X, have already licensed h.264. In the case of free software operating systems, users can choose whether they want to have support for h.264 or not, just as they have for years with any number of other patent-encumbered formats."

Flash (or any other proprietary thing such as activex) is not part of the html or maintained by W3C. It is controlled by a private company.
Flash is a proprietary technology installed as an extension for browser. What flash does is irrelevant.
If people wish to only published information under proprietary extensions and limit the scope of their work, that's their problem. But introducing non-free (as in freedom) part in basic protocols is another story. Internet should be open to anyone.
So please, don't mix up proprietary extensions and standards published bu W3C, which should remain open.

Regardind Mozilla's choice, it is their choice to not support patent encumbered formats. Some approve (like me), some don't. If you wish to fork it, go ahead, code is free.

About other patent-free formats:
"Dirac is great. At some point we'll probably add Dirac support. However, at typical Web bit rates, Dirac doesn't currently perform as well as Theora. The patent situation with Dirac is also currently less clear than with Theora. We'll keep an eye on it." from a mozilla developer.

"You didn't actually answer my question. You keep mentioning things and then forgetting them entirely. Please just make a coherent argument or stop replying. If you're not going to talk sense, you're wasting time for both of us."

I am not here to answer all your questions :)
I don't like to waste my time either so I only answer interesting parts.

"It has been made abundantly clear that they don't have to in order to allow users to use it of their own free will. Just as Apple did not have to implement Theora in order to allow users to view Theora content in <video> if they choose to do so."

And as it has also been made abundantly clear (but not enough apparently), Mozilla is fighting to keep an open web.
So yes, it tries to weight in and try to keep out patent encumbered formats in core protocols.
But that's why Mozilla exist: http://www.mozilla.org/causes/
and http://www.mozilla.org/causes/better.html

"He didn't, actually. He made a lot of emotional appeals that fly in the face of reality and then breezily dismissed every other argument in a single concluding paragraph. I know this because I already read it: http://news.ycombinator.com/item?id=1073718

"He didn't, actually. He made a lot of emotional appeals that fly in the face of reality and then breezily dismissed every other argument in a single concluding paragraph. I know this because I already read it: http://news.ycombinator.com/item?id=1073718

Would have it been easier for you if he had he written "I want to make sure that for anyone, there isn’t a big piece of it (video) that they can’t afford to participate in." ?