De gustibus non est disputandum.Why do you prefer spinach to collard greens? Why do you like Van Gogh more than Matisse? Why do you eat fries more often than onion rings?
I can advance dozens of rationalizations as to why other people should share my opinion that human life is worth more than nonhuman animal life, but most of them will not find traction in any person not already at least slightly predisposed towards that opinion. The value of nonhuman animal life is very much like a religious belief.
If we deconstructed the differing opinions down to their foundations and really examined them, we would likely recoil away in existential horror. The truth is that life has no inherent, objective value at all. The universe is very large, and collides a lot of random atoms and molecules together, and will be entirely unaffected on a large scale whenever some of those random reaction products develop some self-reinforcing complexity.
The only value life has is that which we subjectively impart onto it. And summing up the opinions of 7 billion humans, I generally find that we tend to have a rather higher opinion of ourselves than of any other animal, and the other animals are ranked by some combination of cuteness, cleverness, market price, and deliciousness. But since that's all just subjective anyway, I could still tell the rest of the world to get bent, and just go by my own preferences.