H.264 vs. WebM is a far more nuanced tradeoff – widespread support and higher-quality implementations versus [hopefully] freedom from patents. Either way, the web wins if there's more <video> and less <embed> depending on an opaque binary blob from a single vendor with a track record of platform neglect.
You say "no extra effort", as if widespread platform support, hardware acceleration, more than one high-quality implementation, significant support by authoring software, and direct-to-format hardware capture would happen for free. Avoiding royalties would be nice - although it's almost certain we'd still have lawsuits absent patent reform - but as a business decision that's a LOT to give up.
I really think Mozilla did the web a disservice. They should have implemented platform codec support immediately and added other formats so content vendors could adopt HTML5 video independent of the codec wars
And that's one of the biggest problems with software patents. In 15 years, we'll likely be using a different codec (or, at least I would hope we'd make some progress in that amount of time).
H.264 vs. WebM is a far more nuanced tradeoff – widespread support and higher-quality implementations versus [hopefully] freedom from patents. Either way, the web wins if there's more <video> and less <embed> depending on an opaque binary blob from a single vendor with a track record of platform neglect.