I don't like VN creators using AI at all either but it's understandable to use as a placeholder until an artist can be found. I'm especially more forgiving because CC is this particular creators first VN.
They can't just will someone to become their background artist. They have to find someone that fits their needs and style. That on top of actually finding an artist that's available is a lot harder than people realize. Then they have to procure funds to pay said artist. There's a lot of moving parts when making a VN.