Time to get your learn on: Newton's first law of motion says that objects in motion tend to stay in motion until an outside force acts upon them. It's the law of inertia, which is a fancy way of saying that change is hard. We like to think of it as the First Law of Saturday Mornings. Once you go to sleep, only an outside force (gah, Mom!) can make you wake up before noon.
Well, James Joyce chose Dublin for his stories because "that city seemed to me the centre of paralysis" (source). But paralysis isn't just physical—not for the unlucky characters of Dubliners. Pardon us, but we're going to call it an inertia of the soul. Like when you're so tired, or sad, or conflicted that you just… can't… do anything.
Dead people have a lot more in common with the living in Dubliners than in a lot of books.
If inertia itself makes life miserable, the characters in Dubliners are particularly bad at coping with all of its consequences.