You're welcome, Bethberry (and LadyBrooke).
The subject of whether or not "entertainment" -- fiction, games, movies, etc. -- leads to indifference toward violence will probably be debated forever. But comparatively speaking, it is a very recent issue, if for no other reason than movies, video games, and role-playing games didn't exist until recent times (at least in historic terms). It's entirely possible that some people do become jaded toward violence because of their "unrealistic" exposure to it in such media -- especially in things where you can see the violence "happen," but in such a way that the witness is detached from any sense that the event is, or could be, "real." It has also been suggested (quite some time ago; I wrote a paper on it while I was in high school about 40 years ago) that seeing footage of real violence on the evening news causes the same kind of detachment, and after an initial horrified reaction, eventually inures some viewers to the real horror of it -- because it feels unreal, like the commercials and sitcoms and cartoons one sees on the same screen.
I can well imagine that it's possible that some people are similarly affected by reading about graphic violence; after a time, the descriptions cease to have the same effect they had the first time they were read. Because of my ongoing therapy for PTSD, I have read many books on the subject and related issues; I can't recall which author said it (it may have been John Bradford or Jon Kabat Zinn), but it is nonetheless true: "The witness of abuse is the victim of abuse." One can be as sorely harmed, psychologically, by seeing another person abused as the person who is being beaten or bullied, especially if this is something they see repeatedly, or the trauma is extreme. If this is so, then I would say that the use of graphic violence or other traumatic events in fiction writing is something best used very judiciously. One person might think that an author has a moral obligation to show the truth, the whole truth, and nothing but the truth, harsh and unvarnished and in all possible detail; another might believe that the author has a moral obligation to show as much as is necessary to provoke thought without traumatizing the reader, by making them a witness to verbal violence. I know that it's possible to do so through words alone. I've seen people react both emotionally and physically to brief passages in books; I've even written some things that readers told me prompted similar responses. They also told me that they were quite glad I showed restraint; a little bit went a long way, and too much would have made them feel as if they were being unnecessarily bludgeoned with it when I had already made my point.
So
should Tolkien have written "the truth" about the horror of war in LotR? My feeling is that he
did, in the way that was true to his story and true to himself. I did not come away from my first reading of LotR at age 11, thinking that war was glorious, or that it was something that just happened without causing lasting harm. I felt that it was something terrible, something that any sane person would want to avoid, and that even when it became necessary as defense, there were still many, many people who were hurt and suffered and died, both among the soldiers and the civilians. Graphic detail would not have enhanced this reaction; it quite likely would have made me put down the book long before the end, and I would have lost a great deal by not finishing. Fictional depiction of unpleasant truths can be educational -- but only up to a point, I believe. Beyond that threshold, it can undercut, distort, or even obliterate the message, because the audience stops listening, or listens out of fear.