Hopefully we can both agree that we are having this conversation. :) If so, we believe that truth is real and shared between individuals. Other common facts are sports, world events and books - at times we all look through the same lens. Science is like this too. Science happily ask for you to see for yourself.
Now look at another truth, cigarettes cause cancer. The tobacco industry denied these findings. But now we censor them and their advertising based on this truth. If we didn't censor the tobacco industry, we'd get cancer more often and die.
When we have a clear argument and damages, at least bump them down the page.
If you allow the disinformation campaign to continue, you corrupt the integrity of the system. This can manifest itself in a very ugly and damaging ways, cancer or worse.
It clearly and obviously is not all of these things.
A body of scientists have just recently complained about commercial organisations releasing papers in order to sow doubt. How would Google handle that?
It's judgement calls and subjective decisions all the way down. Any of which can be challenged. I understand why they don't want to do this.
Your truth is not and has never been the same as someone else's truth. The very idea of objective truth is debatable in some of these areas (e.g. "has any nation tried true communism?")
Google is not and should not be the judge of everyone's truths