I honestly didn't find the book to be as awful as everyone else did ( and I'm a 16 year old). I think it was because I had a relation to the little Pearl. I found it interesting how Hester stayed around and took care of the girl, but still saw her as "elfish" and dark in some ways- pretty much calling her a burden. Yes, it was incredibly awful to read, for I had to reread it twice to understand it fully. I recommend it if you are seeking to expand your mind into thinking harder on what words mean or have a connection with.
On the other-hand, I do agree that the characters are extremely dull. Somehow I think even if the writer did not mean to write the story intentionally this way, it contributes to the story. Just goes to show everything was black n grey in the Puritan era. The only thing that I think was not described past boredom was Pearl. She was like a little streak of sunshine dancing through the foliage of trees. That even in Arthur and Hester's guilt/sin, a flower was bloomed in the process. Perhaps conveying the theme that tradition may not be the best way or that certain burdens produce such a travesty.