There are multiple threads like the already.
While I was facing something that can be classified as abuse in my childhood from other children and I had fantasies of horrible revenge and i still have those fantasies of revenge, nothing of that is related to guro in any way because guro is supposed to be erotic and not just hateful.
The reason why i like guro is because it is one of many things I like and i usually prefer happy guro where characters do not suffer or if they suffer they are not emotionally crushed.
I got bored of the normal hentai and wanted something more exciting and extreme. From there, I tried drawing slight toture until it turned into guro.
Drama drives intensity. When a story or an image is filled with strong feelings, it can similarly invoke strong feelings in the audience.
It's hard to imagine stronger feelings than those felt when a person is chopped in half, or has pieces exploded. Imagine it. It's nightmarish. These are among the worst things that could ever happen in real life, and so they are the best things to happen in art, the most intense, the best drivers of feeling in the audience.
All the good reasons why we wish these things would never happen in real life are exactly the reasons why they make good art. By comparison, ordinary art is often tedious.
I was always interested and fascinated by gore and ryona, long before I even hit puberty or understood the concept of sexual desire.
I had a pretty normal upbringing so for me it probably "just is" with the way the brain is wired or something. I don't think its a hereditary thing.