So is this debate about what's best for the future of open standards on the web, or is it about what's best for iOS?Neither.
The debate is about what's best for the web, period. Some people consider open standards to be a priori superior. Others (like Gruber) do not. (I'm taking your usage of "open standard" to include freedom from patent encumbrance.)
Your last statement is a critical point in this debate: You assert that Chrome dropping H.264 support "could help HTML5 <video> see better adoption." This is not an uncontroversial statement, to put it mildly.
I frankly don't see how this move will aid adoption of the <video> element. Yesterday, sites could encode to H.264 and provide a <video> element to some browsers and a Flash container to others. Today, the same is true. Yesterday, sites could encode to both H.264 and WebM. Today, the same is true. The only thing that has changed is that the number of browsers that require a Flash wrapper to play H.264 content has increased.
Sites will potentially use the <video> element over a Flash container for several reasons:
* If they cannot use Flash. This is the case on iOS devices. iOS has done more to drive adoption of <video> than any other factor to date.
* For political reasons. Dropping H.264 support from Chrome will not change this; a site that avoids Flash because it is not free was presumably already encoding to WebM.
* Because the <video> element provides a better end-user experience.
For sites where this third case applies, dropping H.264 support may result in increased usage of WebM. However, note that this is not the same as increasing adoption of the <video> element--dropping H.264 may influence the codec choices of sites that have already chosen <video> over Flash, but it has no influence on sites that are willing to use Flash.
I would be interested to hear your arguments on how dropping H.264 could increase usage of the <video> element in the long term. I just don't see a case for it.
I do see a case that dropping H.264 might increase adoption of WebM. I am, however, dubious. So long as H.264 in a Flash wrapper is a viable fallback, I don't see any site choosing to encode to WebM as a result of this change. (Sites may choose to encode to WebM for other reasons--preference for freer standards or freedom from licensing fees--but in these cases, they would encode to WebM even if H.264 was available in Chrome.)
So, to summarize: You are trying to frame the debate in terms of freedom alone. It is entirely valid to prefer freer technologies and to make decisions based on freedom. This is not, however, the only possible debate, and it is not the debate John Gruber is engaging in. To accuse him of hypocrisy in supporting H.264 but not Flash is to misunderstand his argument.