Earlier quoted context omitted.
That's a generically cynical statement that you don't seem to have any specific basis for. In such cases, for HN purposes you should practice the Principle of Charity and err on the side of giving others the benefit of the doubt. It won't affect Zuckerberg much, but it will make this community better.
You'll find instead that it will turn any community into an echo chamber. This sort of tone policing accomplishes nothing but belittling differing viewpoints and alienating users who may (publically or privately) disagree with charitable interpretations. When the dust clears, you'll have a harmonious web forum -- in which no information is exchanged.
What's the probability they don't know this?
They're corralling the sheeple:
Get typing your sanitised comments. Engagement up.
Weasel Words are kind words.
Correct isn't politically correct.
Motives are always good. There're no bad people in utopia.
There is no marketing. Interviews aren't marketing. HN isn't marketing.