I think it has to do with the subtext (I might be reading into this...) that knowledge is no longer a respected asset, but instead is viewed by some as a symbol of the 'old' status quo (and its related issues and in particular its failure in resolving some of those issues). The reaction to this, as I have understood it, is to either shun those who use knowledge (in the sense of this 'old' way) or outright censor them (remove them from the knowledge-pool).
The article did help in my understanding of identity-politics and why its such a powerful force in the USA and, for example, less so in places like Europe.