- No the argument is that H.264 is still a much better supported format which works much better with an existing workflow, tools and media players (and a negligible licensing cost).
Re-encoding to WebM does me no good if a large section of my target devices don't support it. If they support H.264 but not WebM I'm sticking to H.264, and happily paying the relatively negligible licensing fees.
You also seem to be underestimating the complexity of re-encoding a video library. Its a massive and costly undertaking and hardly just taken care of with a shell script. You generally don't "re-encode" existing H.264 video to WebM. You re-encode baseline video at a higher bitrate down to WebM or H.264 at various bitrates. Frequently these source baseline videos are not stored as digital files - they are multi GB in size. We work with the UFC and re-encoding their content at one point required them re-sending digital tapes to the encoding house so they have high quality source video.
Let alone the actual process.
Even if you own your own encoding tools you generally need to re-encode, QA the resulting video, push it all out to your CDN and then change every link you've got point to the new video URL. If you're not encoding your own video but using an existing service you frequently have to pay for both bandwidth and encoding costs to redo your video you often pay per-minute of video. Its an extremely costly undertaking.