This is a really interesting observation by de Grunwald; it addresses the question of how do organizations become ideologically captured and why is GI so difficult to dislodge. It's easy to imagine that it's youthful, ideologically motivated activists who, once they get hired by these organization, terrorize executive management, by having their hands on the social media accounts and with allegations of micro aggression, lack of 'safety' and all manor of discriminations. And there's probably is an element of truth to that in some cases.
But de Gruwald's thesis that she's pursued in 'This Isn't Working is that the underlying cause is a lack of professionalism and the decline in basic industry standards, in effect that institutions like the CIPD have stopped doing their job. Not only that, but they've lost sight of what their job actually is. I think it's a useful analysis because it answers the twin question of why private and public bureaucracies have become so ideologically driven and why they've become so inefficient and ineffective. We can see that in the NHS, with the national trust, and with the HR function in many private companies.