Why do pigs trample pearls underfoot?
Obviously, they have no appreciation for pearls.
Your interest in pearls is irrelevant to their interest in food, so any time or attention you put into pearls is a distraction from their purpose of getting food. At best, pearls are a delay, a drain that interferes with your role as a potential food source. They want food, but you toss pearls? That’s not gonna work. At worst, pearls totally shift the power balance to the detriment of their food-acquisition agenda and, therefore, constitute a real and present threat that must be eliminated. So they trample away.
But why do they turn and tear you to pieces?
If they decide that you are devoted to pearls, and therefore devoted to the detriment of their food acquisition agenda, then you are a threat, not just your pearls. You must be eliminated. So they turn and tear away.