It's pretty easy. Hacker News seems to think Google seems pretty fair, since we're all "everything is biased and the filter bubble is inescapable, oh, wait, are we talking about Google? Things are great and the government is persecuting them." Hacker News is on the left side of the US as a whole and extremely hostile to Republicans in general and Trump specifically. If HN thinks Google is fair, that's nearly ipso facto proof it's quite substantially biased.

Silicon Valley's lack of ideological diversity is a big problem for them. I don't mean from the point of view of being right or wrong in that ideology, I mean from the point of view of looking out at the rest of the world and modeling their reactions and what they're going to do. Even if the ideology embodied by Silicon Valley is the universe's sole, shining example of true truth and nothing else is even close, they're still going to find themselves having an increasingly difficult time navigating or even understanding the rest of the world, if they can't tolerate any other ideologies within themselves to give them those other perspectives on the world. Diversity really is important.