I agree that DDLC was well-written, and that people are going to like things that are well-written better than things that aren't. I'm also not using the word "art" to say that a creative work is necessarily good. There's a lot of bad art out there, and a lot of it's lazy or empty, but a lot of it did involve effort/love/etc even if things didn't work out.
My reason for talking about the reaction I had to DDLC is just, harm is complicated! DDLC was actually really bad for my mental health. I'm not trying to be special, I played the game and then was triggered for days. It is a pretty clear-cut case of being harmed by exposure to a piece of media, and I'm not the only one who had this reaction. But a lot of other mentally ill people liked the game and found it meaningful, and they would be harmed if it was taken away for being harmful to others, and the writer would've been harmed by being prevented from or harassed for telling his story, and any mentally ill people who wanted to create works with similar elements would've been put in a position where they might feel like they had to choose between giving up or dealing with an amount of hostility they may not be equipped to handle, and that's definitely harmful, too. It's a mess, and there's no way to make sure nobody gets hurt. And it seems like you know this, because you're not writing DDLC off for having badly fucked with some people's heads. I don't think you should write it off, it clearly has value to people, but elsewhere in this conversation you're talking about harm as if it's very black and white and it really isn't.