Why does Fred say it would be ungrateful to drink to scrooges health?

Fred believes it would be ungrateful to toast to Scrooge's health because Scrooge is known for his miserly and unkind behavior, particularly towards the Christmas spirit and those less fortunate. Fred, in contrast, embodies the joy and generosity of the holiday season, and he feels that celebrating someone who embodies the opposite of those values would be disingenuous. Instead, he chooses to focus on the joy of Christmas rather than acknowledging Scrooge's negative traits.