Incest?

So, lately I've noticed that as I scroll through the stories trying to find something to read almost every other story is tagged as incest. This makes me wonder, why? Why are so many people interested in something that is so wrong? I understand scrolling and seeing slash, femmeslash, fan-fiction and all of that because I don't see anything wrong with being gay or fantasizing about your favorite celebrity. Hell, I used to write fan-fiction and still do when it's for a contest, but I don't get this whole incest thing. So many people now are writing about siblings having sex and I just don't get it, not to mention most of them are slash as well. How many people on here know a set of brothers that have sex? I don't think a lot of you do, and you shouldn't. I usually don't write these things as you can clearly see from my page but this is just something that's been bothering me for a while now and I was wondering if anyone could give me some insight on why this has been happening. Thanks.