1. If your receptionist or assistant is only making you feel important, you are wasting their salary. One example: In my job we have to maintain professional licenses in many different states. Assistants help with this paperwork, which is different for every state and requires hours of reading and making phone calls to decipher. Yes, the engineer who bills their time at $150/hr could be doing this, but it's more efficient to pay an assistant. That is one small example of many, many vital tasks.
2. "Goon" is maybe the second oldest profession. Usually we call it "soldier". At some point you may be in conflict with an adversary. It's helpful to have someone on your side who is good at whatever type of conflict that is. I don't know why "telemarketer" is in there, it's not like the others. That's sales, which is pretty vital to any business. Now, the entire business and the product that a particular business is selling might be bullshit, but the job of selling certainly isn't.
3. I think the author vastly overestimates how preventable problems are. Maybe someday we'll invent an airline system that is 100% perfect and never loses anyone's bag. That's not the reality right now, though. Shit happens. Having someone who is paid to deal with it is better than not having them.