Think of these more like a reference implementation to help somebody bootstrap their own compatible hardware design. Hardware isn't the business they're in and

Think of these more like a reference implementation to help somebody bootstrap their own compatible hardware design. Hardware isn't the business they're in and these designs aren't the only way to use their platform. They just make for an officially sanctioned starting point, supported by the legal clarity of an open source license. That making it officially "open source" earns them a news cycle and some buzz is just a little side benefit for what's otherwise pretty common in the industry.