I dont think that this is really true, I strongly suspect that most people I know would consider someone drawing porn of them without consent a majorly icky thing to do, and would probably consider someone doing that to someone else to be a creep for doing so. The reason such drawings are less an issue is at least partly that the barrier to entry is lower with AI, since it takes a certain amount of skill and time investment to draw something like that such as to be clearly recognizable as any specific real person.