I absolutely agree that they can be both; Weinman and MacNeil have proved it. But the 70 million dollar sales of Andy Warhol junk has proven his own statement: "Art is what you can get away with."
Longacre lived through some very troubling decades in U.S history. People were probably happy to just get their hands on a federal coin let alone be concerned about how pretty it was. "If you can get away with it" the mint saves money. The less complicated the design the less stress there is on dies, equipment, parts, etc. Less time engraving, less complaints from banks that coins won't stack.
And the less complicated Longacre's designs were the less stress on him. As a mint engraver, he may have actually been called upon to produce a die from his own design. A thought that must've kept him awake at night.
