Do not forget, android didnt originate inside google.
the history of android is tied to andy rubin, who started out working for apple, then the spin-off general magic, left and started danger inc. (made hiptops using java in much the same ways as android, sold via t-mobile as sidekick), got tired of board of directors meddling so left and formed android, android gets bought by google, now aandy rubin leads android for google.
this is probably also the reason why androids management of third parties are so different from the google "norm". Observe how they made a big fuzz about android market, making it appear to be a part of the general android package. But in reality its part of the closed source google services app pack, a pack that can only be used on approved partner devices (all phones so far). This going as far as sending out C&D letters to devs that provide custom firmwares, with the app pack, on devices already approved.
right now, android is the black sheep of the google herd.