you think
fads are a new invention?

are you seeing them on vintage photos of trucks or pics of currently owned/restored trucks? any option was rareish at the time because these were work trucks - although some owners back in the day may have decided adding a "personal touch" with something they could scrounge was cool, nowadays folks use what they can find to "restore" to their preference, and the car hood ornament was standard on every one of the millions made over a number of years - happens to fit the curve of the truck hood well
Bill