Baccano! is a story with many different plotlines and this is what made it compelling for me. If you don't like stories like Pulp Fiction that focus on different characters and the plot jumps back and forward in time, then perhaps Baccano! is not the anime for you.
If you're not interested in watching a story from the villain's perspective then perhaps you should also avoid Baccano! Many of the characters are interesting, but most are also villainous or at least morally ambiguous. I personally find it fascinating to see a story from the point of view of characters with unconventional morals.
It was overall very enjoyable for me and I liked the "open" ending (even if it's not most people's cup of tea).