The problem with The Lord of the Rings goes well beyond orcs' physical characteristics. It contains references to many real world historical events, languages and cultures. It also has absolute evil and absolute good, and these are associated with real world peoples. Yes the Haradrim, Easterlings and other groups of men aren't pure evil, but they fight on its side.
Some examples:
The Shire is based on rural England.
Anglo-Saxon represents the language of the Riders of Rohan.
The Corsairs of Umbar are a reference to the Barbary pirates.
The mumakil of the Haradrim derive from African elephants.
Gondor derives in part from the Byzantine Empire.
Minas Ithil, conquered by Sauron's forces and renamed Minas Morgul, references Constantinople/Istanbul.
The Battle of the Pelennor Fields is partly based on the 1683 Battle of Vienna which was decided by a Polish cavalry charge.
The Battle of Helm's Deep is based partly on the
1565 Siege of Malta where a small force of the Knights Hospitaller defended the island against the Ottoman Empire.
"Bradford's account of the climax of the siege has a mine exploding with a huge blast, breaching the town walls and causing stone and dust to fall into the ditch, with the Turks charging even as the debris was still falling. He also has the 70-year-old de Valette saving the day by leading towards the Turks some hundred troops that had been waiting in the Piazza of Birgu." - From the Wikipedia article.