That's the French we're talking about. Two points to start with: first, they aren't alone in taking enthusiasm for horsemeat. It's eaten regularly in quite a few countries from Mexico to Japan; second, its place on the French menu is relatively modern. Until the eighteenth century eating horse was disapproved of by the Church and was relatively rare.
The practice got successive boots from the military under the two Napoleons. In 1807, an army doctor, worried by the high mortality and at best slow pace of recovery of wounded soldiers, as an experiment fed his patients horse soup with a dash of gunpowder. Tiens! It worked in many cases.
More important was the decision of Napoleon III, half a century later, that his troops needed to be fed better and should have meat every day. Beef was expensive and so horses were sent to the abattoir. As in other ways, France's conscript army acted as a means of cultural transmission and soon horse was on many family tables. Another factor was that, unlike the UK in the latter part of the nineteenth century, France had no access to beef from its colonies which could have helped keep its price down.
For a Brit "the horse is a friend"
Of course, Napoleon III's hopes for the effect of horsemeat on his men were disappointed. Despite their daily ration of equine cuts they were trashed by the boches in the Franco-Prussian War. That conflict also saw a massive consumption of horsemeat during the siege of Paris in 1870. It was also a staple food in two world wars.
From the 1950's, as beef became cheaper, it fell out of favour and many boucheries chevalines went out of business. In the last few years, however, with increasing pressure on domestic budgets, people have been looking for cheaper meat and some traditional butchers are now offering horse.
But how to explain the repugnance, which talks of a steak de cheval, aroused among Brits (and Americans, too)? This was highlighted across the Channel by the outrage at the discovery of horse DNA in supermarket burgers (up to 29 per cent in the case of the Tesco offering).
During the Second World War, despite draconian food rationing in the UK (50 grammes of cheese, one egg a week) and government urging on its subjects such unusual fare as roast hedgehog and nettle soup, there was no talk of butchering horses; anyway, Churchill, who had a deep sentimental attachment to animals, would have vetoed the idea.
In fact, the horse has a special status in Anglo-Saxon societies. The tearful reaction to War Horse was a case in point. This was underlined for me when I interviewed Penelope Fillon back in 2007 just after her husband had become Sarkozy's Prime Minister: "At our country home in the Sarthe I've got five horses and I've noticed the French seem to treat their horses differently. For me a horse is a friend you develop a personal bond with; the French seem to regard their mounts in a more impersonal way." And so happily have them for lunch.
But Brits shouldn't be too smug: every year, unnoticed by the public, hundreds of horses are deported to Europe where they are slaughtered... and often end up as low grade butcher meat.