I would say that the word 'brutal' is heavy with preconceived notions.

The fact of the matter is that all creatures have to kill to eat. That's true whether what's being eaten is plants or animals.

Having said that, humans are perhaps the only animals on the planet that can recognize a higher purpose in that fact. Like nurturing and protecting what we love. Humans can feel and express gratitude for that fact that other entities sacrificed their lives so that we can live.

Perhaps you could re-frame the question to something like this: Why do people take it for granted that brutality is inevitable but compassion is optional?