Why are we not allowed to be shocked that the museum has acquired Cody Wilson's 'Liberator' handgun, a working firearm, just as another US shooting occurs?

It's the old song. Museum does something sensational. Moralists take offence. Shocked stories add to the museum's publicity. Everyone is happy.

Except all the performers know their parts so well by now that, as in a story by Jorge Luis Borges that compresses an entire novel into a few pages, there is no need to go through all the tedious details. Everyone knows the narrative so well that it can just be taken for granted and we can all move directly to the conclusion, which is that no one is really shocked and yet everyone can enjoy the frisson of the idea that someone, somewhere, some antediluvian fool, disapproves.

Thus the V&A's acquisition of a gun made on a 3D printer has been reported with a mixture of awe at the curator's cultural savvy, reverence at something controversial being done, and respect for the artefact whose groundbreaking nature has now been sanctified by a museum. Far from getting the museum into trouble, its plan to exhibit a working firearm, designed by a self-styled anarchist to give everyone the "freedom" to make a gun at home, only adds to the acclaim for a museum that recently escaped its Victorian image with a massive exhibition dedicated to David Bowie.

It is unfortunate that just as the V&A's gun exploit was settling into the PR bliss of a non-provocative provocation, another "shooter" in America murdered at least 12 people, reminding us that easy access to firearms is a recipe for mayhem. In its cultured way, the V&A is giving succour to barbarism by promoting homemade guns.

It's fascinating how some extreme politics are cool and others are not. If the designer of the "Liberator" handgun had done it in the name of a far right group, there's no way his invention would be in the V&A. Instead, Cody Wilson claims to be a democratic anarchist in the mould of Wikileaks. His violent creation is therefore cool and deserves to be in a museum.

In reality, the idea of freely available gun designs that anyone can manufacture at home (in whatever quantities they wish) as 3D printing looks set to become a routine part of modern life, is terrifying and quite obviously apocalyptic. It's a monstrous perversion of democracy.

What this gun really shows is the human propensity to make the worst of its own intellectual power. Within a few years of the Wright brothers making human flight a reality, war planes took to the air. As soon as nuclear fission was achieved, it was used to destroy cities. Now, as soon as 3D printing opens up a new age of design, it is used to preach the might of the gun.

Does the V&A really want to celebrate that?

What a naive question …