Even at Dickens' time, many people considered the book to be "gushy" and overly sentimental. Others could not stand what they considered an exaggerated view of the sordid side of urban life in London (and elsewhere).
Dickens was very much in touch with his times. The impact of the industrial era and the radical changes which followed are important leit motifs throughout many of his works.
The following references will give you more helpful information concerning the social and economic background of the story and the public reception of this work once it was published (just before Christmas, of course!).