They pretty much lost the war against content farms already. I'm not sure the content indexing & crawling model they have is even adapted to the current web.
The incentives are just not aligned anyways, Google Search gets its money from the ad links on the top, they don't really lose anything if the links below are half terrible...
I'd be surprised if anyone at google would understand that to be a problem, because "It is difficult to get a man to understand something, when his salary depends upon his not understanding it."