In canon it's also clear that the story is from one side's point of view and is based heavily on Bilbo's and Frodo's own record of things. I have no doubt you could find numerous historical cases where exactly the same demonisation takes place. And, underneath, the 'good guys' can be pretty brutal too.
Having read the Penelopiad (events around the Iliad and Odyssey from Penelope's point of view) and other takes on classic stories, I'd have nothing against this on principle.
This. Assume that Lord of the Rings is a historical document of a real world you found. How seriously would you take any given one of the "facts" it describes?
This may be old news to some people, especially the Russian speakers, but I didn't see an article about it here.
In 1999, Kirill Yeskov, a Russian paleontologist, wrote The Last Ringbearer, a 270-page take on Lord of the Rings from the point of view of a medic in Mordor's dying armies who is also a "skeptic and a rationalist." In fact, Mordor represents the forces of reason in this retelling of the story. As a Nazgúl (himself a former mathematician) explains, Mordor is "the little oasis of Reason in which your light-minded civilization had so comfortably nestled." Barad-dur is "that amazing city of alchemists and poets, mechanics and astronomers, philosophers and physicians, the heart of the only civilization in Middle-earth to bet on rational knowledge and bravely pitch its barely adolescent technology against ancient magic."
The story has been newly translated and is available in free PDF form -- in English and the original Russian. There's a recent review from Salon as well.