I have 5.0 badges on my house!!!
No really though, that "5.0" badge symbolizes much more than just the engine size. It symbolizes a message that "power is back and better than ever" marks a chapter in the Mustang's heritage, the benchmark on which perfromance was measured, and a brief time where Ford ruled. Also, got law enforcement a new name "Five-oh". Yes, that "five point oh" badge means a lot.
Ford made a stupid mistake going to the 4.6, they lost confidence with the people,lost face as the Japaneese would say. They should have kept it 5.0L even when they went modular, like they finally caught back on, just took them 15 years.