Margins on mining are low (possibly negative), you have absolutely no pricing power, brands are worthless (a hash is a hash regardless of who makes it), and your profitability is largely determined by what other people (not you) do. Does that sound like a business model that Google would be interested in?
I would find it much more likely that a Google would attempt to buy a company like BitPay then get involved in mining.
Very accurate and well-thought, I definitely agree.
Acquiring something like BitPay would make sense once they start believing Bitcoin can't be stopped: they would have a profitable company which could directly integrate in their services.