> The big issue with a phrase like "don't be evil" is that it is ambiguous and highly depends on the understanding of the word "evil" to the individual that reads that line.

That's a feature, not a bug. If you think to yourself:

"Self, is this truly evil? Are there no redeeming factors or are the consequences more heavily tilting to the negative than the positive?"

And the answer comes back: "Yes this is truly evil. No, even from a consequentialist perspective you shouldn't do it."

Then you should speak up. Even if only 1% of Google's employees see something from a certain light and speak up, that's enough! It doesn't mean they get final say, but it encourages a conversation where there might have been none. At the end of the day they can always quit in protest.