Remorse matters, to me. But it's always hard to know if remorse is real or not. Many criminals cry in court after being found guilty, speaking of how sorry they are. It is noteworthy that they were not crying and speaking of sorrow BEFORE they were judged by society and put away.
It also matters that what Vick did was not a one-time passion violent act. What Vick did was something he thought about and did for years, for money. He did it in secret, knowing it was criminal He witnessed the cruelty on many occasions and was fully aware of the suffering of the dogs. Yet..he continued for years. That is very different from losing your temper and kicking a dog once. The long term cruelty shows a person's inner character, what they are made of at their core. Not many people have the heartlessness to do what he did. He set himself apart from normal people. That lasts forever. Remorse, forgiveness....all this matters. But all that does not remove what he did. It does not remove the suffering of the dogs, the fact that some died, and that some will never be normal or happy. It's a miracle that many have been rehabilitated, though, thanks to some caring organizations and people.
Let's put it this way. If someone had abused YOU for years, and esp if they made money on it, seeing you suffering, bitten and bleeding, raped and chained, starved, abused...then after the person was arrested, convicted, and served a bit of time....THEN said he was sorry...would that put you at square one with that person? Would you be with that person as if those actions had never taken place? Of course not. That is impossible. What happened, happened, and like a rock thrown into a pool....the ripples from those actions were created. The rock cannot be un-thrown. Forgive, if you want. But you cannot forget. That is impossible.
It is said that the best predictor of future behavior is past behavior. If Vick really had caring and concern for animals in his heart, he never would have done what he did. I think what happened after his conviction is that he was treated like scum temporarily by those he cares about, and that shocked him into wanting to act like a normal person and be considered normal, again. It is not caring for animals that is at the heart of his behavior.