I suppose there's a few different kinds of thieves around.
But, when it boils down to it, the only consistency I can draw across the board is that thieves think the world, or people in it, owes them something and they shouldn't have to do any real, honest hard work to earn it. That said, those that steal to make a living tend to believe that they do not possess any other skills and abilities that would otherwise give them the same quality of life they get from stealing.
Some believe that honesty is for chumps and that society and the good people in it exist only for them to prey upon (I think this is a false sense of self-worth as to thinking of themselves as 'the wolves' and everyone else 'the sheep', imply a position of power they have over us).
But, when we consider the value a career thief has to offer society, we find them coming up substantially short. Imagine if every career thief dropped dead where he stood, what would society lose? A few mouths to feed? Last I checked, they didn't pay income tax? Now, imagine the reverse... the honest people thieves steal from all dropped dead where they stood. Well, I don't think the remaining people would last long. An extreme example, most definitely, but I think it illustrates their role in society: parasites and pests. No better than the squished cockroach under my boot.
Unfortunately it's not so black and white... there are people who have weak moments and take advantage of an opprotunity to better themselves with other people's possessions. We all probably know a few of these people, probably on different scales... regardless of just how small or large their crimes are, it's still a crime, still taking advantage of others and stealing from them. And it's wrong.