Its not who we are, but what we do that matters.
I don’t know who said it first, but I heard it in Batman Begins, and I always wanted to use it. Why do I use it here? Well I watched Public Enemies (2009) recently and it seemed to fit the idea quite well.
Johnny Depp portrays the character of a real life criminal, specifically a bank robber John Dillinger in this movie. Set in the early thirties this film focuses on the more famous robberies committed by Dillinger, Baby Faced Nelson and Pretty Boy Floyd, two other infamous criminals, and the attempts by the Bureau of Investigation (now the FBI) to stop them. Christian Bale plays Melvin Purvis, a Bureau agent in charge of the investigation. These are two of my favourite actors, and as expected they do deliver admirable performances.
So the Bad guys do Bad things, the Good guys try to stop them and succeed in the end. A Happy ending? Not by a long shot. See, this is what happens when you change perspectives in a story. Every one has a human side, a statement which is a topic for discussion on its own, even the worst men. Focus on those moments of humanity and you can turn Hitler into an anti-hero. We draw the line between Good people and Bad based on what we see them do, once we start analysing the reasons behind their actions, the line starts getting a little blurry.
In my opinion, crime cannot be justified. Because the moment you start, you are bound to come across a moral roadblock, a point where you may not be able to continue justifying it without becoming a part of it yourself. People tend to have a fascination for powerful and enigmatic criminals. For some its a secret, for some its not. In the beginning of the movie we see John Dillinger being treated as a celebrity, even when he’s arrested people want to take pictures with him. Infamous, yet a celebrity nonetheless. A law-breaking criminal becomes a symbol for a luxury that normal, law-abiding people cannot afford – doing what they want. That’s the image people carry in their heads when they fantasize about the life of a powerful criminal. Money, Fame, Women. The rest of the movie tries to break that image by showing the consequences of committing crime. There are two things that you sacrifice when you lead the life of a criminal – true happiness, and a moment of rest without having to look behind your back. But on this topic, I am in a state of confusion myself, so it may just be my opinion after all.
There have been other movies, where the audience is made to feel for the villain, or in that case the anti-hero, so there are no surprises there. Being an adaptation of a non fiction book, they have stuck to the facts, so it would be wrong to judge the movie on its plot. The acting is great, the 30s ambiance is perfectly rendered, there is plenty of action, and though it does tend to slow down at times, overall its one of those movies you can watch in a theater and not be disappointed.
From the Audience Seat 
A very interesting insight. I must also compliment you on your stylistic felicity. Also interesting is the point you raise about people being fascinated by criminals. The romanticisation of crime as well as criminals can be found in literature also, the most famous being Professor Moriarty perhaps. Definitely looking forward to watching this movie.