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Suggesting that businesses are short sighted because they use Google as a primary traffic source is simplistic. It might be nice in your niche to be able to do that, but quite frankly it's not true across the board.
Eg: if Google and all it's products disappeared tomorrow I would lose perhaps a third of traffic and a quarter of revenue.
Risk aside, why wouldn't you develop other revenue streams? Even if you could guarantee and secure a high ranking in Google, those other revenue streams still represent good money, surely?