Who's story is this? Nobody. - Who's nobody? The average working man.
This story is very old but very relevant. The common man's opinions are disregarded. His needs are manipulated. But of course the story makes clear that he is key to society.
The story shows that. Then the narrator comes in and rather dramatically reinforces that point in the final three paragraphs just in case you missed it the first time. Yes, there's a pretty high soapbox. Yes, it's pretty holier than thou. But hey, it's Christmas time. What's so funny 'bout peace, love and understanding, anyway? And that's quite a trick on Dickens's part.