Why is it important to me? Well first, because it is my RIGHT to know, which should vaguely familiar. I don't think that my NOT being on the list would drive the chances of my house or family being targeted by violent criminals statistically high enough to start obsessing about. I certainly don't want my kids playing at a house that contains guns, as they are much more likely to be shot accidentally in such a house. If I have a neighbor, friend or relative who I see progressively going off the deep end, it would be nice to know if that person is packing. These reasons may be based on some far-fetched scenarios, but no more far-fetched than owning a gun to "protect-my-family" or as a "check against government".
I do see the argument against publication, which is why I said the publication of such information was "probably out of line". Only "probably", because gun guy's right to privacy does not trump my right to know.