All of the articles, particularly this one, seem to be missing the point. They attribute Google's actions to abstract ideas of openness or competition between codecs.

But there is a concrete issue involved: under MPEG-LA's licensing terms, Google should be paying $6.5 million a year to distribute a H.264 decoder. Under that license, the end users only get the rights to use the software "for personal and consumer purposes": they couldn't fork Chrome, redistribute it, etc. The Ars article mentions this, but immediately moves on.

It's possible Google expects MPEG-LA to try to enforce the patents, and that's why they're dropping H.264 support. After all, Google is the only browser vendor not in MPEG-LA worth trying to get money from. The yearly licensing amount just went up by $1.5 million, which might have influenced the timing of the announcement.

Comparisons with Flash are irrelevant: it may be less open than H.264, but not in the way that matters to Google.