I see DS9 as being just as optimistic as TNG. Just, less dogmatic in that optimism.
Now that I think about it, Doctor Bashir I Presume.
I always hated the idea that people would get blacklisted based on the crimes of their parents. Or, if they did get blacklisted, why don't they get high paying private sector jobs outside the Federation? And then they create one special exception for somebody who just happened to get away with it for long enough and none of the other genetics say "Hey, wait a minute. Why not me then?" They just didn't think that arc through at all.