A bit of yes and a bit of no, really. There are good parts to the ending, of which Gradgrind's reversal from his earlier obsession on facts is clearly one. Likewise, to a certain extent, we all enjoy Bounderby's end after all of his blustering. However, two elements stick out to us as being perhaps rather unfair. Firstly, Stephen Blackpool's death strikes a rather depressing note, and secondly, Louisa and the way that she is still marred by her upbringing and is condemned to be alone also strikes me as being rather sad.
I don't really think it's tragic. It seems that in some ways good wins out in the end. Gradgrind realizes how wrong he has been in the way he has raised his kids and he is going to reform. Bounderby is exposed as a fraud and Tom has to pay for the crimes that he has committed. It really seems like there is justice in the way the book ends. Since I did not feel emotionally attached to any of the people for whom the story ended badly, I don't feel that it's tragic.
I think that if one defines "tragic" as a situation where protagonists are forced to see their own perceptions of reality inverted and revealed to be false, then I believe that there is a sense of tragedy in the ending of Dickens' work. Consider the last scene where Gradgrind speaks with his son. The setting of the circus ring, an endeavor that Gradgrind dismissed as "fancy," and the dialogue between both father and son. The father, articulating conditions of emotion and the heart, while the son coldly quoting facts and "laws" of economic determinism is a moment that represents the ultimate in repudiation of father's beliefs. I would consider such a scene to be tragic because Gradgrind's beliefs are all inverted and this is recognized in a sad and pathetic manner. The fact that Gradgrind at the end commits himself to "Faith, Hope, and Charity" makes this repudiation complete.