I have to say that I find your willingness to censor content that you personally don't like quite disturbing. If Patreon had instead banned hardcore porn instead or even porn in it's entirety, you'd most likely have a vary different opinion. Do gay people have the right to take away your hetero porn? What if it was a ban on tattoo/piercing/interracial/anal/BDSM porn? This is a serious set back for free speech rights and anyone who thinks otherwise clearly doesn't fully grasp the gravity of the problem. You may be happy because you don't like the content they're banning, but as the saying goes "Hate speech is free speech". You should be fighting to stop censorship.
I won't argue the legality or morality of incest porn and to try to argue pedophilia would be to tie my own noose, but I do remember reading something once that speculated that Japan's fetish porn actually helped to reduce sex related crimes. What if by taking away the porn that these people enjoy just exacerbates sex crime rates? Taking away incest porn isn't going to make people stop liking it, they're just going to be frustrated that they can't get it.
If you aren't willing to fight Patreon's censorship, then I hope you don't complain when they next encroach on something you do appreciate.