As I have engaged this work, I have encountered a definite lack of sympathy for the wrongly convicted. Attitudes range from, "Why waste your time on those people" to the outright accusation that I am aiding and abetting crime.
It is sad, but true, that a number of wrongful convictees are criminals - they just aren't guilty of the particular crime they are currently serving time for. A common attitude is that the wrongful conviction got that criminal off the street, preventing him or her from committing more crime, so Justice was served after all. And they comfort themselves with the assurance that the criminal who did commit that particular crime will eventually get caught for other crimes, so there's no real harm done.
I admit it's difficult to argue against that rationale. However, let's make it a personal application. Most of us use credit cards. How would you feel if Person B charged something on your card without your permission, you reported it to the Card Company, and their response was that you have made other charges to your card and just because you didn't make this one, doesn't mean you don't have to pay for it. And, at some point in time, someone else will charge something against Person B's card, which he'll have to pay for, so it all comes out even in the end. Doesn't make sense, does it? Even if you are irresponsible with your credit card use, you still do not deserve to be charged for someone else's purchases.
So, even if some wrongful convictees are criminals, we still are not serving Justice by convicting them of crimes they did not commit.