The thing with this guy is that his observations seem to really boil down to this:
A recent grad's (I assume he was an MIT undergrad, not Sloan MBA) adjustment to the real world.
It comes across as a young man who was adjusting to the realities of the workplace (which happened to be consulting) -- from that of a student.
For many of us who have worked for a while, we all know that in academics/school, analysis drives the "result" or "answer". In the real world, it's far more murky than that - analysis plays a part, but so does that very messy issue of human dynamics.
Engineers learn very quickly that the most technically elegant solution isn't always the feasible one - it comes down to budget (or lack thereof), deadlines (unrealistic or not, set by non-engineers), politics, and so forth. Or even when engineers have to choose a vendor to work with - it's not always purely an analytical exercise whom to choose.
It's called the real world, and I think the author simply had trouble reconciling that with the ideals of an academic environment.
It seems like he had a hard time accepting the fact that F500 companies hire consultants beyond the "numbers" or "reports" - but that consultants serve as political tools and political capital to further the agendas of certain constituents within an organization. If you the exec can't get something approved by the Board (for some reason or another), having the BCG or McKinsey stamp (a 'respected' third party source) as allies to your opinion can help in getting the Board on your side. And sometimes the junior consultant on the team may not have access to the bigger picture of what's really happening within the organization because they are tasked with only the specific project at hand - so it may seem like the "answers" or "results" of a project make no sense on their own, but could make very good sense in the bigger picture.
One of the more amusing things the author mentioned was how he had a tough time with the workload being greater than his motivation to work -- which seems to apply to virtually every single day job all of us have ever had, right?

It's called the real world. We've all had those periods in our work lives where we get up in the morning and go "oh God, do I have to work today? Ugh." But most of us man up and do it.
And compared to the world of politics and public office in any country, business looks like a religious seminary.