Nietzsche wrote Beyond Good and Evil, which implies that both are part of the universe. Professor Pangloss was Voltaire's mockery of Leibnitz' 'The best of all possible worlds' in his satire Candide.
Panglossian optimism seems to imply that nothing bad is really bad because it all works out for the best. This is a confused and confusing way to view reality, though could well apply to the ego-future of Musk&Co.
Voltaire, though a rationalist, had the attitude that we should 'tend our garden', meaning the Earth, prefiguring Rousseau's state of nature (and of course Ralph Waldo Emerson, Walt Whitman.) In a garden things are either good or bad. Slugs can be bad for lettuce; compost is good; water and ponds are good; Japanese bridges; too much neatness can be bad.
In The House of Elrig (prev), the young Gavin Maxwell and his buddy in the Highlands have a habit of turning over dead rabbits to see the disgusting creepy crawlies lying underneath, hookworms. While such things can't be said to be evil, there are places where it's not your place to be.
Vultures are obligate scavengers because they are totally dedicated to their task of stalking the dead. They have to be internally tough and outwardly cleansing, disinfecting themselves to survive the corruption.
Even if it would be stupid to think of vultures as evil, they are associated with corruption and have evil connotations. Pigs are also associated with corruption, and are 'unclean' to Jews. In Hebrew, Beezelbub (devil) means lord of the flies.
So corruption as a general thing has bad connotations. But, clearly, the bad has to be present since an overly tidy garden can also be bad!
Panglossian optimism seems to deny the fact that things are definitely bad (repulsive) and that they have to be controlled, tended as in a garden. The key person there is the gamekeeper, who figures also on The Housecof Elrig.
A traditional gamekeeper does not have the egotistical convictions of a lab-scientist, and does things which can be considered 'bad' like shooting foxes and crows. Everything a good gamekeeper does is to balance forces of predator-prey and to maintain fertility.
Corruption is a necessary evil of nature that the crows and ravens are there for. Ravens are another harbinger of destruction. These beastly things will peck the eyes off newborn lambs and calves
Evil in that sense is a connotation in nature, and one has to set against it a catastrophically psychotic tidiness (see TofF2 Babcock Ranch.) Clinical tidiness detaches the human from corruption or rotting pig manure, and we are told (by 'them') it's all a matter of DNA and numbers.
This denies the strength that comes from the bad and the good together in a physical situation of disorder (decay and revival.)
Disorder allows the strength of mechanism to function; the vulture's intestine that is knotted cords of muscle. Clinical tidiness is the illusion that enables scientists to treat DNA as a type of organic computer, the product of number and weakness of psyche.
A balance of seeming opposites, dirt and cleanliness, depends on a feuding state of affairs for rugged strength. One can't have order that's not tyranny; DNA is a tyranny of 'fact' masquerading as an illusory order. Fitness can only be a product of rugged strength, not number and weakness (ego.)