Maintaining a professional distance while in the workplace makes sense by itself, but it's inconsistent with the "bring your whole self to work" policy that the author cites.
Google somewhat prides itself on it's 'open culture'[0] and I'd say that this is not only well known, but is a point of pride in it's hiring process and a recruitment tool. The ethos of talking about anything and everything is celebrated and encouraged.
To then have an 'open' culture in every respect except with racial issues (broadly defined here) as indicated by the memo's author, does not square.
Sure, the OP here may agrue that a work first culture is better (and I agree to a certain extent), but that does not fit within Google's culture.
The memo's author is correct to point out the mis-match, and in the open culture of Google should be celebrated for doing so.
If they do get flak for it from higher-ups, then I think it is fair to state that the open culture of Google is de facto dead and Googlers should adjust.
Happily for HNers, this means that the FAANGs are on the way out and their 'moats' may start to develop holes that can be exploited by start-ups. Look out for the greybeards sooner than later as the elves start to leave middle earth, so to speak.
I think most people are freer than they believe to bring themself to work.
Even at companies in rural areas, people can generally be somewhat "weird" or "alternative" and still be accepted at work if they don't make their personality a weapon to annoy people with.
