Because if Google is biased against conservatives, Democracts don't stand to benefit from helping point it out. Pointing out that complainers disproportionately come from a certain demographic does not automatically invalidate the complaint. Why is it mostly left wing people complaining about fake news or hate speech on these platforms, why do most complaints about misogyny come from women? Is it because the complaints in question are fabricated, or because one portion of the population is disproportionately affected?