I was very intrigued while I listened to your recent cast on admins & trip reports.
Couldn't agree with you more, on the value proposition, or as you say the manager economics 101.
I work for a very large multinational IT organization, and am paid very handsomely for my services.
Admins for us, went the way of the do do many years ago. I travel each and every week to my current engagement. I have to book my own travel (air, travel, car rental) each week. Yes the firm provides us tools, but again to the value proposition you point out, it's pretty lame for us to be doing this.
Furthermore, I then have the privilege each and every week, of entering in my expenses, printing them off and forwarding to HQ for reimbursement. If I deviate from approved levels for any expenditure, I must then plead my case to the accounting Nazi's. More non-value add time.
I'd be curious, if you had any insights to how one might turn this leviathan of an enterprise around, to examine these most idiotic practices.