Short version: dear God but some people just like to complain and kvetch about the least little damned things.
Slightly longer version: seriously, LORD OF THE RINGS: RIDE OF THE ROHIRRIM is good. It’s very anime, but it’s also good. The main characters are engaging, the two major secondary characters are hysterical, and the story doesn’t mess around with the larger History. JRR Tolkien would never have signed off on an animated version of anything Middle-Earth related, but if you pressed his shade the blessed soul would likely grudgingly admit that the production was done in a way that was mindful of what he wrote.
It’s not going to make a lot of money, and that’s a shame, but at least I got to see it in theaters.
Some of those little things are huge pet peeves for some of us.
Mary Sues are overepresented in anime, but that doesn’t make them less obnoxious. (I’m looking at you, Kirito.)
There’s a place for children to understand war better than people who have been studying and practicing it for years, but Middle Earth isn’t Ender’s Game. The concept isn’t appropriate for the milieu.
Heroic self sacrifices can be powerful. But if it could have been easily avoided in the moment, and happens only to clear the deck for the Main Character, the writer deserves to be pelted with rotten vegetables.