I see what you mean about Enron execs, but I'd like to think UPS is slightly more than an elaborate ponzi scheme.
The sectors are certainly different and the shipping business model is certainly far more transparent than a company that was essentially just buying and selling the price of energy, but that by itself is no guarantee that the boardroom doesn't have a broader agenda that's beholden to an ideology that runs contrary to the stated goals of the union it has grown accustomed to dealing with from a position of strength.
No company in ALEC wants to come out of a negotiation with it's union emerging stronger. I wouldn't put it past the board in Atlanta to lose a little if they thought the union lost far more. This "TA" is that in name only at this point and the company could just as easily withdraw all of it a week into a work stoppage if they thought there was a good enough chance that O'Brien saw an exodus of UPS hourlies after all the gains they assumed were money in the bank just weeks prior were suddenly gone like a mirage in the desert.
I think we need to be prepared for all possibilities and not just "Eventually the company will yield to hourlies, the general public, big institutional investors, etc." For many years, the largest holder of shares was the Casey Foundation, an organization sharing the last name of the company's founder. When that foundation took issue with UPS's growing role in ALEC, it's not as if the company altered it's course even in the slightest. If the C-suite doesn't care what the largest shareholder thinks, then they might not care what anybody outside that isolated insular circle thinks.