Some people may say this because they have become more interested in other forms of media. Visual novels require a certain level of time investment to read through the text and make choices, and if someone has a busier schedule now, they might prefer something quicker like a short - form podcast or a mobile game that doesn't demand as much time and concentration. Additionally, the art style in some visual novels might not appeal to them anymore, or they could have outgrown the often - targeted younger - audience themes in many visual novels.
Another reason could be related to the cost. If someone has been buying a lot of visual novels and they find that the price doesn't match the value they get from them, they may decide to stop. Also, there could have been some negative experiences with the community around visual novels, such as encountering unruly or inappropriate behavior in online forums related to the genre, which could turn them off from the whole concept of visual novels.