Are orcs actually evil?

[Boromir88]

Arathor, I'm afraid you are mixing the Orcs Tolkien created with the common stereotypical view of Orcs that is common in literature. See, Tolkien created Orcs that are much more complex and have the human feelings of individualism and free will. What you've said completely contradicts what we see Orcs are capable of doing in Tolkien's story.

First you disregarded Letter 153 where Tolkien directly says that even Orcs were not beyond redemption, also consider these...

1) The Orcs were certainly capable of rebelling against Morgoth and Sauron:

“The Orcs were beasts of humanized shape (to mock Men and Elves) deliberately perverted / converted into a more close resemblance to Men. Their ‘talking’ was really reeling off ‘records’ set in them by Melkor. Even their rebellion critical words - he knew about them.”~Morgoth’s Ring; Myths Transformed

2) We see a glimpse of a more humane side of Orcs with the discussion between Shagrat and Gorbag:

’They would,’ grunted Gorbag. ’We’ll see. But anyway, if it does go well, there should be a lot more room. What d’you say? - if we get a chance, you and me’ll slip off and set up somewhere on our own with a few trusty lads, somewhere where there’s good loot nice and handy, and no big bosses.’
’Ah!’ said Shagrat. ’Like old times.’~The Choices of Master Samwise

Even Orcs had a desire to settle down and get away from the 'big bosses.' Sure we see them as the spiteful, hateful, ant-like slaves of Sauron and Morgoth. Yet they were much more complex than that stereotypical label. They could not be part of the 'cogs' of the machine. They could rebel and they could feel a desire of individualism.