<video> in fact can specify a non-free codec. This isn't about the types of codecs that should be allowed to be included in <video>, it's about the types of codecs a browser vendor will support out of the box.
Fonts are much smaller than video decoders so they can be sent over the wire, making the whole licensing and distribution thing the problem of the person using the font on his site. Fonts are all decoded by the same free code, whether that font is free or not.
There is no facility to transmit a decoder for the use of <video> tags on your page, and no one would do that anyone because it would be a huge nightmare to make sure you're sending one that can run on the user's platform, the browser would be forced to allow execution of an arbitrary binary block that could very well just be posing as a video decoder, and then all sites would have to pay for the rights to distribute the license. It just doesn't work. The browser has to include the decoder locally, so the browser vendor has to decide if he's going to pay for the license for a H.264 decoder or not.
Fonts are much smaller than video decoders so they can be sent over the wire, making the whole licensing and distribution thing the problem of the person using the font on his site. Fonts are all decoded by the same free code, whether that font is free or not.
There is no facility to transmit a decoder for the use of <video> tags on your page, and no one would do that anyone because it would be a huge nightmare to make sure you're sending one that can run on the user's platform, the browser would be forced to allow execution of an arbitrary binary block that could very well just be posing as a video decoder, and then all sites would have to pay for the rights to distribute the license. It just doesn't work. The browser has to include the decoder locally, so the browser vendor has to decide if he's going to pay for the license for a H.264 decoder or not.