I agree that "these laws are hurting the gun-control cause", but the editorial really doesn't address that much.
The main way that GC laws hurt the GC clause is by driving more non-owners to become owners, and more owners to become "even-more-owners." Each time gun control becomes a galvanizing topic, it does so for both sides. When GC advocates start pushing hotly for more controls or bans on, say, so-called "assault rifles", more people who had only given a fleeting thought to becoming owners of such firearms go out and buy them, fearing that the freedom to choose to do so may be taken from them. Many of these guns end up in homes of people who are poorly-equipped, mentally and logistically, to have them (for example, they lack safe-storage options, mental safety discipline, or they have irresponsible cohabitants with them.)
The main message for would-be gun-banners should be to stop yapping about banning guns, and we'll stop panic-buying them all up. Then, we can work on addressing the real motivations behind each side of the argument.