If you think that bias is a bad idea than Googles current approach seems okay. They don't bias against WSJ, but they don't bias for WSJ either - The Google bot has less material to work with, so their is less content compared to other sources, so it has a worse ranking. No bias.
Setting "don't be evil" aside, Google's only responsibility is to Google.
But here's the rub. Google's product is its users' attention. If they bias their search results enough, (maybe) they lose product inventory.
How much is "enough"? Probably much more than filtering WSJ.
But IMO bias in a search engine – a presumed oracle of truth – is evil. So there's that.