Tolkien has them, frequently-made claims to the contrary notwithstanding. Some examples just off the top of my head. (And while I’m a fan of The Hobbit, I’m not particularly a fan of The Lord of the Rings; a fan could probably come up with more examples.)
• Thorin Oakenshield. Greed exerts a regrettable influence over his behavior throughout The Hobbit, especially toward the end. Obviously he’s not evil, but he’s not exactly an angel either.
• Beorn. How do you categorize this guy morally? He’s basically benign, because he just wants to be left alone. But he’s also a threat. Bilbo and the dwarves are urgently warned not to leave the house while he’s outside it in bear form. He captures a goblin and kills it, which is morally fine since the goblins are planning on attacking a nearby human settlement. But he also lops off its head and mounts it on a stake outside his property, and skins the warg it was riding and nails the skin to his wall. Presumably the goblin and warg were in no position to care by then, but it’s rather Hannibal Lechter. You want to ask Beorn, “Um, dude? Are you…okay?”
• The wood elves of Mirkwood. Tolkien sums them up as, on balance, “good people” and “not wicked folk.” But also, “If they have a fault it is distrust of strangers…They differed from the High Elves of the West, and were more dangerous and less wise.” That’s putting it mildly. When the dwarves, dying of hunger and thirst, approach their revels to try to beg some food and drink, the elves’ response is to disappear. Three times. Later they take the dwarves prisoner. Their King, in particular, is completely unreasonable about holding them prisoner – even if they wait “a hundred years” – just because they won’t tell him what their quest is. Like it’s any of his damn business! (And he’s avaricious: “If the elf-king had a weakness it was for treasure, especially for silver and white gems; and though his hoard was rich, he was ever eager for more…”)
• Sauruman. Starts good, happily allows himself to be corrupted by dreams of power.
• Gollum. Good (as Smeagol long ago), then bad, then good, then bad.
We could also include some marginal cases:
• Tom Bombadil. Now Bombadil plainly is good, not evil, by temperament. Still…he won’t join the fight against Sauron, and in fact acts indifferent to the whole War of the Ring. He just lets other people fight that fight. That is not heroic behavior.
• Even the hero of LOTR, Frodo, succumbs to temptation at the end. This is a marginal case because he’s been exposed at length to the most powerful malign magical object in the world, which, we’re told, no one can resist. But still. One could make a similar point about Boromir, by the way.
Of course there are also lots of good characters and evil ones.
So all in all we have some unambiguously good characters, some unambiguously evil characters, and some morally in-between characters. In other words, everything. This is more “broad-viewed” and “nuanced,” not less so, than work that only has morally ambiguous characters! What’s broader: A work that has black, white, and shades of gray, or one that just has shades of gray?
None of this should be taken as a denial that LOTR is essentially a good-versus-evil story. But to say that everything in Tolkien is black or white, with nothing in between, is to depart with breezy nonchalance from the actual text.