They could have reacted with a "Google does not support or endorse the views expressed", and let the rest happen naturally.
This is censorship. Yes, it's within a privately owned company, but it is very clearly a suppression of intellectual debate. Why not encourage this debate to happen?
This black-and-white, all-or-nothing trend in public speech in general is very concerning. Debate and discourse no longer exist, it's simply one side flaming the other.