Incest was not the reason, as his games dont have ANY piece of it. In the main menu of both games, you can even read that incest will be not part of his work.
I suspect he was bullied until extreme limites and/or he deleted himself from Patreon because he was enough of all that criticism against his MISFITS finalle.
Most people are correct when they say this game had been completed with a incomplete feeling, but some people have gone more far and had insulted the dev, i believe. Most probably he gived up because of all this people bad reaction with the end of MISFITS.
Hope one day to see his third project become true.