Like others have said here and I've chimed in in other similar threads...
It's 100% all about that "Taboo Naughtiness" factor. The... "We've all thought about fucking that hott (Insert Taboo relation) but we all know it'll never go beyond just fantasy...", so here's the sexual outlet for it.
Official studies and surveys into the trend agree that it is all about the forbidden taboo factor. And that even though the "consumption / viewership" stats amongst the populace have gone up even as high as 500% according to some articles I've read... that those willing to talk about it answer ovvvvvverwhelmingly that they would never, and have never, engaged in such activity due to the simple fact that it is personally, societally, and most importantly legally "damning" to be outted as engaged in, or in the pursuit of incestual sex. A lot of articles also tie in the attraction to ancient times of "pure blood lines" theories, and "genetic attraction" theories... if you care enough to read about those... I don't haha.
Why do I watch / enjoy faux-cest scenes...easy
Cory Chase

... Kimmy Granger

Alexis Fawx

.... Kendra Lust

Brandi Love

.... Lia Lor

Sydney Cole

... Dava Foxx

Dakota Skye

... Lilly Rader

Lauren Phillips

.. Whitney Wright

Princess Berpl

.... Xev Bellringer

Princess Leia

.... Rebel Lynn

Mindi Mink

.... Cadance Lux

Molly Jane

.... Kenzie Reeves
Soooo many more...
Just out of this world hottttt MILF & Teen Porn category pornstars. Simple as that... they're gorgeous and I love to watch them get nailed by huge hairy cocks or going at it in some lesbian fun.


And the taboo factor of course... member of the ovvvvvverwhelming majority here ^_~