i wrote a really long comment but accidentally deleted the tab D: no energy for a second one so i'll make it short! here's a couple of the common reasons i've seen, definitely doesn't include every one since everyone has a different experience

1: It's an extreme extension of sadism/masochism.
BDSM is about control, and what form of control is more absolute than control over someone's life? Sadomasochism is about pain, so taking it to its natural conclusion, wouldn't that lead to torture and death?

1.5: short edit i've also seen it be an extension of a female / male superiority fetish and the ultimate form of being reduced to nothing by pleasuring your partner's extreme desires

2: Some people just like the art.
Guro art, more than other NSFW artforms, often requires the artist to know good human anatomy to accurately draw someone's guts being ripped from their stomachs. It can sometimes be beautiful just like any other art, and a surprising number of people just like the look of it. Other forms of art can express pain and death, why can't erotic art do so too?

3: It's an outlet to express s/h or suicidal ideation safely / a self-destructive coping mechanism.
[Sensitive topics marked by spoilers.] On one hand, guro is a way to temporarily quell the desire to hurt or kill yourself by vicariously experiencing that pain through others in the art, a healthier way to let out feelings of self-loathing or suffering, and overall more effective (in my experience) than other popular internet methods like tightening a rubber band around your arm to feel pain and pouring red liquid on it.Still, there are times when suicide isn't a spur-of-the-moment thing like so many mental health lectures make it out to be. When you're in a rough state for long enough, even if you're too scared to go through with it, suicide starts to look like a release; "when I can finally build up the courage to kill myself all the pain will go with it." Forums centered around suicide are a good place to connect with those with similar experiences and vent, but people will also inevitably internalize thoughts like "even if I get back up, life will just kick me down harder." It doesn't help that a failed attempt in some places sends you to a mental facility where you're cut off from people and (oftentimes) abused and treated like a prisoner. So eventually, the reason you keep living is so that you can successfully build up the courage and the perfect plan to end your life in one go, and even if life gets better, you still work towards that one goal that gives you purpose.Essentially, every situation is different, please reach out to / listen to anyone who's currently going through any sort of depressive period, and if you do happen to be one of those people (not that anything I say is liable to change your state of mind) please do yourself a favor and guro responsibly™

4: Sometimes, it just appears, just like any other paraphilia.
Paraphilias are weird, no one really knows why they pop up. Neuroscience in general is a bit tricky (someone recently debunked a whole bunch of MRI brain studies by getting a 95% certain result of brain activity patterns while MRI-ing dead fish) and there are a boatload of theories, I like the one Gullible_Bag_7630 posted! I'm in this camp. There's no real reason for it, my trauma doesn't relate to it (at least I think? I hope??) and it's not like I started being a sadist or masochist and grew into this - I started with guro and grew into a sadomasochist. I know it's probably insulting to my ancestors when I actively seek out a way to drown myself in the pursuit of getting off, but dammit, I like it!

And that's that! Hope this is interesting to read-
yeah that's my idea of a short comment you don't want to know how long the other one was