What seems to be the reason for the way Cratchit emphasizes that Marley is dead at the start of the scene? Why does he say that this piece of information is going to be of value of the story?

The references to signifiers of time are numerous in the chapter; the bells ring to herald Marley's arrival, and even the repetitive discussion of Marley's death at the beginning emphasizes the present tense in which Scrooge is stuck.

Why the present tense? Capitalism functions in the now. Always aware of the clock, of how much time has passed and how much is left, capitalism is foremost concerned with what can be done at the present to accumulate money. Scrooge believes Christmas time is simply "capitalist time," to coin a phrase, whereas Fred believes it constitutes a departure from capitalist time.

Scrooge's temporal problem, then, is his inability to hold a more humane version of the present tense. Moreover, he is unable to combine the three tenses, past, present, and future, into a singular redemptive vision of humanity. Scrooge foreshadows the concept of the epiphany when he asks for all three ghosts at once; perhaps the epiphany somehow depends on time in such a universal way.