Actually, the Innocence Project (IP) has confirmed the guilt of more people than they've exonerated, it's just that when they demonstrate the likelihood of a wrongful conviction it tends to be newsworthy. I'm not against IP. As I posted earlier, when the wrong person is convicted of a crime --even when this person is otherwise a scumbag, it still means that somebody else got away with it.
IP has an uphill battle. For one, every single person in prison is, in their own words, innocent. IP receives thousands of petitions a year, the vast majority from folks who are truly guilty of their crimes but are hoping that IP might be able to work some magic and let them out. IP has to sift through all these petitions trying to separate the truly guilty from the small few who might not be. It's a rare and newsworthy event when IP actually finds a wrongful conviction and this is a testament to the integrity of our sometimes imperfect criminal justice system.
If IP was getting people released every week, I'd be worried. Fortunately, IP "victories" are rare -and this is a good thing.
Which is almost all of them, as you say . . . .
The only one I ever met who cheerfully acknowledged his guilt was one of "my" Mariel Boatlift prisoners that I interviewed as part of a local bar association project. He had a rap sheet long as your arm, and he seemed proud of it rather than otherwise.
I think IP does itself and the system a disservice by trumpeting their successes as though that is the norm.