Humans have exploited and preyed upon other humans since the start of recorded history despite laws designed to curb such behavior. This fact is the ultimate slap in the face to the imaginary belief that humans are superior to nonhumans. But if you want to have human rights, you must have nonhuman rights. If you do not give them consideration, you leave a loophole that allows humans to justify discriminating against other humans, since racial supremacy and religious supremacy and gender supremacy are the same in principle as human supremacy-they are based upon an unproven personal opinion “special status” that Nature (or invisible deities) does not acknowledge in physics, weather, or other phenomenon.
Morality is not perfect. The inability to avoid all harm to nonhumans does not negate the principle. The failure to eliminate homicide or child abuse (or choosing to save the life of a familiar over a stranger in an emergency situation) does not justify concentration camps. The same can be said for farms and vivisection labs. If humans want laws to curb their behavior they must extend this to other beings out of fairness. Only humans require such laws and can be held to them-non humans obviously cannot, they cannot be shown to make ethical claims of superior worth and unfair discrimination, and to punish them because they cannot do something you know they cannot do is as fair as expecting a blind man to read a warning sign. Humans who knowingly break laws are afforded more respect as criminals than guiltless animals.
Morality does not follow a hierarchy. If human problems always come first then one could further refine and prioritize them based on the importance of race, gender, age, religion etc.
Nonhuman exploitation by humans is due in large part to domestication which requires immense effort to maintain. By contrast, human slavery, child abuse, and homicide have existed as long as humans have, and will likely continue to do so as long as humans can reproduce. The elimination of the former is a more realistic hope.