I think there are some things to care about in terms of ethics, like recognising when it's actually being used for dangerous things like coding malicious software or whatever, but I don't think lewdness is the kind of ethics that a text generator should really be worried about. There's not really much harm to be had in it being used to write even the most morally depraved smut. People are already producing that by the boatload without the help of AI.