Its not as true today as it was a thousand years ago but we are still very detrimental to ourselves and others. We hurt others for survival and pleasure locking animals in tiny cages when they could otherwise fly around the world or crawl around a natural environment freely. We also hurt innocent people while seeking justice as we dont know right from wrong so many get punished when no real crime has been committed. All throughout history we have punished people according to moralities we claim are objective while we have to admit that they were wrong and subjective only to put out faith in another subjective morality thinking its objective. A person freeing slaves would be considered to be a hero today but would be a villain in the past. Gay people used to be abominable and now they have equal rights. Murder may have been considered wrong back then but we define it differently so actually what we call murder wasnt considered to be wrong or at least not all of it while what was murder back then might justifiable today in some situations depending on who your asking. I think we should simplify morality and use it to get what we want out of the world and avoid what we dont want out of the world while not taking advantage over anyone else making right and wrong fair and unfair. We want the same thing out of life that we want out of games which is pleasure so i say we set up rules to where everyone has a shot at being happy with the idea that no ones happiness is more important than anyone elses. Equality fairness and what we desire out of life gives us objective morality. Its not fair to kill when you dont want to be killed so on and so forth. And if we go by objective morality the right thing to do is kill yourself so as to avoid "necessary" evils or at least not have kids as bringing life into a cruel and unfair world is cruel and unfair and you shouldnt hurt anyone as you dont know what they deserve. If you dont know right from wrong you should be striving to learn it so as to be as blameless as possible if there is a god if you need a selfish reason. But blindly accepting a morality from your local church or parents is moral laziness that results in the unfair treatment of many different types of people and the perpetuation of traditional cruelties which is probably the most punishable act itself as without learning right from wrong you will be wrong most of the time. .
Human beings have been absolutely terrible for non humans, and in many ways we've been horrible to humans too- however, humans cannot be detrimental to the human race- if humans were to not exist, the human race would be in a far worse state than it is with us. Every other creature, yes. But not including ourselves.
Nothing and no one is. Compared to any other animal on Earth, we've had the luck to develop that pesky pre-frontal cortex that enables higher thought. This makes great feats of ingenuity and manipulating our environment possible for us humans, albeit not always for the best.
However, aside from the fact that without "evil", being "good" would loose it's value and vice versa, humans are capable of changing their mind. As long as that is possible, we could learn to structure our societal systems more responsibly, utilize our tools for altering the environment around us by humbly recognizing our limitations and - most importantly - educate people. Nonetheless, yes, there will always be a dissenter - that too for either greater good or detriment - that will stir up conflicts. Humanity might be a risk for it's own existence and perpetuation, but any complex, self-organizing and self-aware system would inevitably be as well. Life might have been less prone to derail if we were nothing but ants in harmony and unity, but I'd like to think that one would rather keep their flawed ability to gain knowledge and face our mistakes than having a mindless existence, or basically, no existence.