I want to say I don't understand this. I want to say that if s/he was making others happy, then God would understand and encourage him/her making the world a better place. However, I've not had this kind of encounter. In turn, I wish him/her luck in what he is doing and I hope one day s/he returns to finish what s/he started.
I doubt it has much to do with sex, violence, or swearing in his writing. If what he says is true, he believes he had an Abrahamic experience with God. In the Bible, an angel appeared to Abraham and told him to go sacrifice his son to God. This was Abraham's only son with his wife, Sarah, and God had promised Abraham that he would father a great nation. Abraham obeyed, reasoning that if God asked him to sacrifice his own son, God would equally be able to raise the boy from the dead, or provide another child to keep his promise. However, before Abraham could make the sacrifice, an angel stayed his hand and God provided a goat for sacrifice instead. The idea here is that a believer must be willing to give anything God requires of them, especially those things to which they cling most dearly. The author believes he has been called to leave his writing behind in the name of following God, probably because his obsession for writing sometimes becomes an idol in itself.
I don't know why people on Reddit are giving him flak for this. "Something more important came up" for him so they should just respect that.
