Why would we need to see parents in every game? That's another question. Dead or not, they don't need to be center of attention. If it's not an incest of course (yeah yeah). And even then, no need to show every single relative living in only one family house. Some may live their life in other town. I mean, death in such case as this game just playing "so you don't need to think\care about them". To remove player's possible questions. But as far as i can see, MC's parents, especially dad, would play a very significant role for the plot later on.