I'm convinced Android being open source is just an accident of history. It's been somewhat useful for Google to be able to ride on that goodwill, but they're not actually invested in open source beyond the ways it directly benefits them (or at least they haven't been in the last 10 years). Thus they're happy to throw the baby out with the bathwater if they believe they need the bathtub for anything that will earn them 0.1 cent more than that baby would.