Using a hard-nosed, for-profit approach in a nonprofit world, Clark collected both admirers and detractors among antihunger advocates, who were accustomed to more genteel methods.
Last year, Clark, who made $141,300 annually, helped create the nation's first nonprofit supermarket in Chester, known as Fare & Square.
At the outset of his tenure, Clark merged Philabundance with the Greater Philadelphia Food Bank, which had been foundering, according to Patrick Druhan, a director at the Montgomery County Community Action Development Commission.
"He deserves kudos for that," Druhan said. "Bill has been a hunger champion."
Mary Summers, a food expert at the University of Pennsylvania, agreed.
"Bill is an impressive person who figured out how to create systems of providing emergency food to a scale that served large numbers of people," she said.
While Clark's intelligence and innovation have long been praised, his methods sometimes inspired disappointment and anger.
He was derided for poaching food from fellow food banks, an accusation Clark denied.
And hunger fighters outside Philadelphia excoriated Philabundance for diverting food donated by their local supermarkets to feed the city's prodigious hunger.
Clark was unavailable for comment. Previously, he defended his tough businessman's approach, honed in the private food industry.
Clark has worked in advertising; was a product manager at Swift & Co., maker of Soup Starters and Brown 'n Serve meats; and owned a specialty foods company that made soups, pastas, and salad dressings.
Clark contended that it was folly to fight hunger without a bare knuckles approach.
"You wouldn't want the Red Cross to run the blood supply on good intentions alone," he once said.
Clark particularly tangled with antihunger advocates in Chester County, where State Sen. Andrew Dinniman (D., Chester) accused Philabundance of "sparring" over territory. Specifically, Dinniman said Philabundance was using its power to undermine the work of the Chester County Food Bank.
Clark denied the charge.
In a previous interview, he acknowledged that he tends to rub people the wrong way.
"In my lifetime, my approach has been called aggressive, forceful, and a few words not suitable to print," Clark said.