Art isn't anything which can be quantified in a single sentence as it unique to the creator and the audience.
It is my opinion that everything benefits from moderation, including art. Depravity and excess do little to enhance while often having a harmful effect. This is where boundaries are beneficial but like art itself, boundaries are unique to the person and where I may have a boundary, you may not as is evidenced with the above referenced episode. I believe the story was harmed by the grotesque narrative being created for the Klingons, a narrative not previously disclosed for any Star Trek species that I can recall, certainly not a prominent species that has been at the very heart of Star Trek since its inception. It would be as if Andorian antennae are really for sucking brains out of the skulls of others through the ear canal.
Oh great, I just reminded myself of a movie which gave me sleepless nights, Skyline.
I'm saying that aside from the fictional aspect of this episode, I find it troubling and yes, disturbing that upon learning of a person being eaten....an already deceased person no less that someone wouldn't be revolted by this. Just because it is a fictional story doesn't change or lessen the degree of comprehension and thus the reality of what was stated. I try to avoid sensationalism which over time can lead to desensitizing my conscience and subconsciousness and this episode certainly fell under that category for me, as did Skyline, Hannibal and many other art forms like them.
In the realm of Star Trek, my humanity or even all of man kinds humanity isn't the baseline for every other species just as in reality, we could very well be visited by a hostile force as in Skyline but this is where boundaries are useful. Not everything we can imagine, dream up or envision ought to or should make its way to print.