How Microsoft made money from Android is quite interesting, and very ORACLE-like: Microsoft went around threatening OEM companies to pay up for a bag of patents it claimed Android infringed, but wouldn't publicly disclose which patents those were. Meaning OEMs couldn't create work-arounds. The mobile IP-wars were something.
I don't know, but if so, is that relevant? The question was whether or not it was a good deal for Google. It's not zero-sum.
Your argument was it was a good expense because it is popular, yet an uninvolved company is making more, so perhaps the purchase was unnecessary.