I'm fairly certain the other stuff would have fallen into place if a codec was widely supported.
edit: actually I suppose this is covered by "browsers failed to support WebM as well as they support GIF." but it's confusingly worded since Microsoft and Apple basically don't support WebM at all, and the widespread usage that leads to a better interface (in the browser and in forum software) depends on that.
I wouldn't mistake its prevalence as evidence of any failing of <video>. When people -want- video, they know how to post, embed or share it. While geeks care about plug-in-free video, the people sharing animated gifs do not.
Ideally I'd replace those GIFs with a bunch of JPGs and a touch of javascript to cycle between them. It would even allow me to have the animation only start when the image is first visible, whereas now it just cycles indefinitely. But all that would require a bunch of work and the animated GIF was easy to create.
PS: I need to go pester the posthaven guys to implement auto cycling of photographs in their galleries to replace the ugly GIFs.
[1] http://blog.corujas.net/summer-recipes-gazpacho
[2] http://blog.corujas.net/summer-recipes-francesinha-portos-fa...