For me, writing about the darker side of things - emotions, state of mind, violence, gore, etc. - is a way of sharing my personal experience with those in need. (Not to say I'm a war veteran or anything; I can't enlist because I can't take orders, I know that much about myself. It's just that my family hunts, so I know a decent bit about violence, bloodshed and gore anyway, and I've got a fair bit of experience with mental issues, my mom's after-rape trauma and behaviors, and whatnot, too.)
Mostly when I write dark things, it's because either I'm trying to work through something or I know someone who is. Sharing experience helps. A lot.
Sexual kinks.... I write those because I'm into bondage, I have a visceral need to be made to submit by someone I trust - my bf - because I flat can't fully relax and just go with the flow otherwise, and toys and unresolved sexual tension are wonderful ways to up the ante in an intimate situation. Exhibitionism I might write about, but frankly that's on my strictly-fantasies list because while the risk might be thrilling, getting caught...wouldn't be. And if/when I write a story with exhibitionism, I will throw that into the tale because it's something that should be thought of.
I thoroughly agree and/or understand where Attackegg and JayDee are coming from. If only there were more out there so willing to be themselves, with no limits. If society won't accept you as you are, at the very least here online where we can be relatively anonymous and share the things that really matter to us, then there's something wrong with society. And if those of us who are writing about dark things can't do so here and be accepted, then what are we supposed to do? Suppressing the need to express these - urges, cravings, whatever you want to call them - that only makes them worse.
Make sense? Not trying to call anyone unaccepting or a bigot or anything, I just am a brutally honest person and this site is somewhat of a haven for we oddballs and outcasts and deviants, and I both applaud and am grateful to you for trying to understand (a mind as open as yours is a wonderful thing). Just trying to point out where I'm coming from. And anyway, there's always the search, and you never have to click on any links except the ones required by the mods and admins, so really this place is for everybody. *frown* Perhaps a better way for me to put the above bit is: this is a place where we can go and not have to hide, where we can be one of the crowd even if not all of the crowd is okay with our particular tastes, and we treasure that.