I think one important issue is that not all domestic violence is created equal.
You have cases like one mentioned earlier, where a fight got a little out of control ten years ago or whatever, and a guy shoved his wife. Poor decision. They make up, he doesn't do anything violent to anyone for ten years, and he still can't buy a gun? I am sympathetic.
You have cases like a drunk fight between college roommates five years ago that had the police called in by a neighbor on a noise complaint... well, they're roommates, so BAM, domestic violence conviction. Poor decision, but I am still sympathetic.
But you also have FREQUENT cases where there is a pattern of domestic violence that only generates a conviction for maybe one in two dozen actual incidents. The abuser's family is living in constant fear and for many reasons is reluctant to report the abuse. So this guy has a long history of disregard for the welfare of his own family, anger management problems, and willingness to use illegal violent force for his own ends. But hey, it's only a misdemeanor. You know, it's not like people with issues like that ever end up escalating their abuse up to and including homicide. Or anything like that.
However, all of these incidents do have something in common- the person with the conviction did something violent and stupid. While you can reasonably say that some of them are being punished in excess of what the circumstances of their crime deserve, none of them would be punished at all if they had gone through their whole lives without offering violence to others... like the overwhelming majority of us do.
Everybody's actions have consequences. The consequences may be too harsh in some cases, and so I think it's reasonable to lobby for exceptions or a process to regain your rights, but I don't think anybody sitting on a DV conviction can whine about how "somebody done me wrong!"