death, disembowelment and writing

i often wonder about the level of cruelty that drives a person to write me to write.
a long time ago, in a different life that i once had, i was told that people who become shochets (jewish ritual slaughterers) and butchers are often driven to do so because they have, somewhere within, perhaps a drive towards violence, or murder, or lust for blood, or any of these bizarre things, and so this field is almost like a safe way of having those desires manifest themselves in something positive, like the killing and cutting up of animals for food. (disclaimer: i have no idea who told me this/where i read this, but i'm tempted to say that it was during a telephone discussion with someone having more jewish knowledge than i did at the time.) it seemed to make sense on some level: a person picks a profession based on their interests. of course, one could just as easily become a surgeon: blood, gore and good deed. whether or not i believe that there is any divine force that enters into this (i do not) isn't the issue. the issue is in cruelty.
i once had a student say to me "wow, this writer is really twisted to come up with such stuff." he was referring to the very last bit of steinbeck's grapes of wrath. (i'm not going to give the end away, sorry.) i've heard the same phrase used to describe stephen king's work. and that of charlotte perkins gilman. i've received comments from people saying the same thing about my own work. one of the best writing professors i've ever had, made the point that one must torture his/her characters. "whatever happens, make it worse. keep making it worse."
so i torture my characters. and sometimes, i make it worse and worse, but i don't make it better. so i torture my readers as well. sometimes i show such cruelty to my characters that i have to stop writing for a bit, just to regroup and remind myself that they're not real.
is it more cruel to be in a profession in which one regularly causes death and dismemberment and butchering and disemboweling? is that a healthy manifestation of whatever cruelty is inherent in the human psyche? is that an acceptable and normal way of acting on it? does one's profession has anything to do with one's personality? how many people in this day and age would gladly take a job clopping cattle on the head before sending them to their death? or, in jewish slaughterhouses, slash a cow's jugular (or whichever vein is being sliced open) with a specific ritually prepared knife in order to kill them?  or is it crueler to be a writer, where one routinely creates characters to torture? and where one may or may not hide bits of reality in fiction, as a way of torturing those who have wronged that writer?
do writers of psychological terror possess a higher level of cruelty than writers of ABC books for kids?
and when i torture my characters, am i more cruel than a butcher/baker/candlestick maker?
are killers of cows more cruel than killers of chickens?
if i still lived in the world of ritual slaughter, would i have been a knife wielding maniac, wearing blood-spattered hip boots and rubber coveralls, waiting anxiously for the next animal on my line?
would meatballs and spaghetti still taste as good?