CW: Depression and child abuse
DDLC rightfully critiques the genre of dating sims for its tendency to normalize unhealthy relationships, and it does so throughout its dialogue. There are times when the protagonist responds to a situation as a typical dating sim protagonist would, but does not receive the reaction expected from the characters. Instead, the characters respond in a way true to reality, rather than enhancing the fantasy this genre typically presents.
One such example comes from Natsuki's first scene. When she explains that her friends would ridicule her if they knew she still read manga and that she doesn't know how her dad would react if he knew, the protagonist says that since he's reading with her now, she should be happy. She tells him that "it's not like that solves any of my problems" (Salvato). The protagonist assumes that his attention somehow makes up for her mean friends and abusive father, but in reality this makes no sense. Her life does not revolve around the protagonist, and he can't make all of her problems better just by hanging out with her. The protagonist's argument is grounded in the logic of a typical dating sim: that the player should get to see just how happy Natsuki is that you chose to spend time with her. Her response challenges this logic and points out that even if she's happy to spend time with you, her life is much more complicated than whether or not you choose to date her.
The protagonist continues to think he can solve all of the character's problems, and he is proved wrong by Sayori. When she tells him that she has depression and explains how it affects her, he reacts in perhaps the most selfish way possible. He gets angry with her because she didn't tell him sooner, and then claims to know what's best for her. This behavior is completely unhealthy and once again assumes that the protagonist knows best and can somehow make everything better. The game refutes this logic when Sayori tells the protagonist that what he's saying isn't helping her, and that it's in fact making her feel worse. Still, the protagonist ignores her and maintains the idea that his attention can make all of her problems go away. DDLC contrasts the typical logic of dating sims with the reality that the protagonist's words could actually be quite harmful to someone with depression.
DDLC's characters have aspects of their lives which are unrelated to the protagonist and which he cannot change. This challenges the unhealthy portrayal of relationships found in other dating sims by showing that the protagonist does not have total power over the girls' lives, and that a relationship with him is not a transformational experience that fixes all of their problems.
I agree, I think the harsh reality that Doki Doki Literature Club brings to the genre is an interesting take that plays off of player expectation. The reality that is real life problems and relationship dynamics don't exist in Dating Sims, and when they are introduced they create a harsh disconnect. I like your analysis of the shock value it introduces. To me it was especially jarring to see such a realistic implementation of depression. As someone who doesn't play traditional dating sims, it was still jarring to not be able to actually do anything to help Sayori, the reality of depression, that one person in three days cannot help a person who truly needs help was one I did…