On Downer Endings

I watched the ending of the animated series Berserk yesterday. I was on the verge of being physically ill.

I'm conflicted about downer endings like that. On one hand, I wonder if the sheer level of pain, sadism, inhumanity, hopelessness, and, well, evil had to be shown on screen. I just wasn't ready for it. I've seen some really shocking movies and shows, but Berserk is perhaps the one that disturbed me the most (and it's a cartoon, even). It haunted me for the rest of the day; every time I closed my eyes I flashed back.

On the other hand, perhaps the creators ought to be commended for stirring these feelings in me, as was undoubtedly their intent. Does my discomfort rob the ending of whatever artistic value it may have had? Does "artistic value" hinge on whether you come out of something feeling good? The purpose of the ending was to define "evil" using moving pictures, projected onto characters the viewers had been made to care about over the course of 25 episodes: The point of the excersize was to make the viewer feel sick, and at that, the animators succeeded.

So I suppose the question is, on what does art hinge? The artist's ability to make the viewer feel what the viewer wants to feel? Or the artist's ability to make the viewer feel what the artist wants him/her to feel? That is the crux of my conflict.

(All I know for sure is that I will never complain about Evangelion having a depressing ending ever again.)