To extend the previous commenter's simile - a man is a _product_ of his genetic code, but is also affected by environment. Bringing it back to the point at hand - yes, you are right that people can make bad code with good tools, but they'll be _much more likely_ to make good code with them (and vice versa).
This Ask HN is not about "the code that should logically be best" but "the best code". There is no need for likelihood, people who have worked on it can report whether it is the case.
And people here seem to praise the tooling exclusively...
I would also point out that good tooling makes for good code, but big scale makes for bad legacy code. It is not at all obvious to me which of those effects should prevail at Google.