We use Google because the results are useful, not because they are "unbiased". Ranking implies some sort of "bias" and is what makes search results generally useful. We don't want a search engine that does nothing clever and just spits back unranked results. Otherwise, we would be inundated with results containing credit card scams, porn, Bitcoin scams, Viagra ads, etc, when we search for... pretty much anything.
In privacy (incognito and not logged in) mode, all of the above still applies. What would NOT apply is something like: You are a vegetarian and suddenly all of your restaurant searches rank vegetarian restaurants higher in results while in privacy mode. Unless, of course, for some reason people in your general location happen to mostly eat vegetarian.
In any case, if people don't like it, stop using Google and go use some other search engine; there is absolutely nothing holding you back. More times than not, I think people will switch back to Google because they find the results more useful, even in privacy mode.