In "A Christmas Carol", what reason does Scrooge give for not joining his nephew at Christmas?

First, Scrooge
basically says that he does not like Christmas, and so he has no desire to celebrate it. He
describes it as the following:

"a time for paying
bills without money; a time for finding yourself a year older, and not an hour richer; a time
for balancing your books and having every item in 'em through a round dozen of months presented
dead against you."

In other words, Scrooge seems to
feel that this is a time not only when people are financially irresponsible, spending money they
do not have, but also, by extension, that this is a generally unprofitable time for individuals
in general. Scrooge values money, and Christmas, to him, is just a time to spend money, so he
does not like it. He does not place value on family, relationships, compassion, love, and so
forth, and these things might compel him to go to Fred's house; he only values wealth, and
Christmas depletes it, so...