Because OHA was just a way to make people think that Android was an open collaboration between the many companies involved. In reality the companies were all subcontractors to Google to get the first handsets launched. I know because I worked for one of them.
The ecosystem, and really the whole mobile marketplace, have drastically changed since 2011.
Not that it's illegal, but if Google and other massive companies were openly involved in an illegal venture, wouldn't that be reason enough for it to be on the front page?
Perhaps it's on the front page to illustrate how quietly it's been dumped and how different it is from the status quo.