Are orcs actually evil?

[Erurin]

I do not view it as genocide as much as extermination.
The Orcs of Middle-earth were incapable of any motive besides violence and self-preservation. After the first generation of orcs, they ceased to be mutated Elves and were, very much so and only so, Orcs. They stopped being the Children of Illuvatar and became monsters of Morgoth, like the spiders of Mirkwood- though bred by Morgoth and birthed by the Maia Ungoliant- were no longer Maiar. The Orcs were unredeemable, unswervingly evil.
So the killing of thousands of Orcs is justifyable if one keeps in mind that when Morgoth twisted the Elves bodies, he twisted their souls and minds, too.