I think it's a good question. Other than Yellow no company will purchase a Teamster NMFA company due to the pension liability. Thus Holland or whoever, was useless to any company other than Yellow.
My guess is Zollars thought the economies of scale would benefit Yellow, he never realized the impossibility of merging multiple teamster companies into one. That has never occurred successfully before.
He should have spun off Holland & New Penn as debt free companies and just kept the long haul businesses. Then concentrated only on that until it made a profit.
But no matter Sean O'Brien was hell bent on puting Yellow out of business.. He refused to listen, work or even deal with management to save 30,000 jobs.
The tough guy teamster won....