Firstly, a reminder: This is not tiktok and we just say the words incest and pedophilia here.
Secondly, I don't know if I would call them 'interests' so much as fixations or even concerns. There are monstrous things that people think about, and I think writing is a place to engage with those monstrous things. It doesn't bother me that people engage with those things. I exist somewhere within the whump scale, and I would hope no one would think less of me just because sooner or later I like to rough a good character up a bit, you know? It's fun to torture characters, as a treat!
But, anyway, assuming this question isn't, "Do writers know they're gross when I think they are gross" which I'm going to take the kind road and assume it isn't, but is instead, "Do you think authors are aware of the things they constantly come back to?"
Sometimes. It can be jarring to read your own writing and realize that there are things you CLEARLY are preoccupied with. (mm, I like that word more than concerns). There are things you think about over and over, your run your mind over them and they keep working their way back in. I think this is true of most authors, when you read enough of them. Where you almost want to ask, "So...what's up with that?" or sometimes I read enough of someone's work that I have a PRETTY good idea what's up with that.
I've never read Robert Jordan and I don't intend to start (I think it would bore me this is not a moral stance) and I've really never read Rice's erotica. In erotica especially I think you have all the right in the world to get fucking weird about it! But so, when I was young I read the whole Vampire Chronicles series. I don't remember it perfectly, but there's plenty in it to reveal VERY plainly that Anne Rice has issues with God but deeply believes in God, and Anne Rice has a preoccupation with the idea of what should stay dead, and what it means to become. So, when i found out her daughter died at the age of six, before Rice wrote all of this, and she grew up very very Catholic' I said, 'yeah, that fucking checks out'.
Was Rice herself aware of how those things formed her writing? I think at a certain point probably yes. The character of Claudia is in every way too on the nose for her not to have SOME idea unless she was REAL REAL dense about her own inner workings. But, sometimes I know where something I write about comes from, that doesn't mean I'm interested in sharing it with the class. I would never ever fucking say, 'The reasons I seem to write so much of x as y is that z happened to me years ago' ahaha FUCK THAT NOISE. NYET. RIDE ON, COWBOY.
But I've known some people in fandom works who clearly have something going on and don't seem to realize it. Or they're very good at hiding it. Based on the people I'm talking about I would say it's more a lack of self-knowledge, and I don't even mean that unkindly. I have, in many ways, taken myself down to the studs and rebuilt it all, so I unfortunately am very aware of why I do and write the things I do most of the time. It's extremely annoying not to be able to blame something. I imagine it must be very freeing. But it ain't me, babe.
Anyway, a lot of words to say: Maybe! But that might not stop them from writing it, it might be a useful thing for them to engage with, and you can always just not read it.
Also, we don't censor words here.