I'm generally optimistic about our future. When I look back on the past, I don't really see any time where I would have preferred to live, and that's considering that I'm a white male. When I then examine the past from less privileged perspectives, I am even more grateful that I live in the time that I do.
Certainly, we have our problems, but I believe that we can use the various crises around us today to help focus what we need to improve for the future. I believe that Dickens was trying to convey a similar belief. He was bringing to light many dark areas in his society, but his novels usually carried a glimmer of hope--hope that society could improve and that times would get better.
I think that might be why he is one of the English language's most celebrated authors.