Well, it's both, I guess. He uses the extreme body of work to explain that he's got the experience and then some to tell them that this is a managerial and academic failure of nearly unprecedented proportions.

He's not some tenured professor sequestered in the bubble of academia.

At a school that large they need to defend why their leaving matters.

It's an open letter: he want's others reading it to know who he is, and why his opinion should matter.