There is some truth to what Ginsberg asserts (i.e., administration could most certainly be leaner at a lot of places), but the notion that administrators are disconnected from "the pursuit of knowledge" is a bit weak in my view. A lot of the reason for the growth of Ginsberg's "administrative class" can be attributed to the growth of research programs at universities. Administrators are primarily there to worry about real-world issues that most faculty can't be bothered with in the cut-throat world of publish or perish. These include checking regulatory issues (i.e., establishing policies for IRBs and medical research), aiding in grant preparation, outreach efforts, and balancing academic freedom with legal issues. These are all things that faculty do not have expertise in, as PhD programs do not train them for these kinds of responsibilities. Frankly they shouldn't worry about these things- they're there to do research or teach, not draft a policy. You could argue that administrators might be overcompensated perhaps (especially at the upper-level), or that there might be too many of them, but their necessity as a distinct organ of the university is indisputable in my opinion. The halcyon pre-70s days when faculty could regulate a university on their own are gone (and it's questionable whether or not they ever did a particularly good job at this to begin with).

It’s possible that Ginsberg doesn’t really see this as much because he lives in the world of political science, which doesn’t require nearly as much support infrastructure since it is so theory-centric.

You also might want to take what Ginsberg says with a grain of salt for the very reason that he’s a tenured professor with a salary of around $157k a year (http://web.jhu.edu/administration/provost/docs/JHU%20Fact%20...) while most administrative positions (perfectly fireable at the first sign of economic trouble!) at JHU are in the $40k-$50k range (based on Glassdoor). He’s not quite the victim of brutal administrative oppression that he claims to be.