Maybe, but I suspect people are just irrational about guns.
My father’s background is Jewish, which means no one in his family ever hunted. (It makes meat non-kosher so there’s no tradition of it, and even non-practicing Jews like my dad see it as foreign culturally.) My mother’s from the UK and was raised Quaker, which she continued practicing when I was a child.
So I grew up in a fairly anti-gun family, and have fairly anti-gun values myself. I’m uncomfortable with guns, don’t like the idea of people having guns, and don’t think guns generally are an asset to society. Nevertheless, years of reading the SDMB have convinced me that many gun laws are poorly crafted and misguided, and have caused me to distinguish between those of my anti-gun beliefs that stem from analysis of factual data (the minority) and which are related to my personal values and preferences (almost all of them). [Take that, people who say GD never convinces anyone!] I’ve also seen how many people who share those values and preferences don’t make that distinction when it comes to guns.
Even people here who usually require cites and empirical data make claims about guns and violence based on “common sense,” assumptions, and anecdotes. The OP said that “it seems” to him to be a bad idea, apparently based on nothing more than gut feeling and speculation about the law’s enforceability. The very first response is about how the idea “strikes” the poster. People ignore the fact that there often is data to be analyzed, and it doesn’t always conform to common sense.
But that’s just human nature, and most of us do it, on both sides of this–and every–issue. I don’t think it’s a conscious decision to fight weak cases for “the principle of the thing,” as often as it’s the fact that it’s hard work to figure out which of your beliefs are rational and which are not.