I tried to buy some ox kidney today. It is a favourite of mine, moreover, it is a perfect iron boost. But no luck. Not even the neighbourhood specialist butcher gets it in very often anymore.
As the butcher said, people don't eat it, so the abattoirs don't bother keeping it.
Hopefully, after a period 'out of fashion' offal eating will come roaring back onto the scene.
I've had enough silly arguments with people who think eating offal is an indicator of 'peasant' origins to suspect that prejudice is one cause of its decline. There are probably others. Not knowing how to cook offal and not liking the taste, are two that come to mind.
Those latter two are fair enough. But, a good cook can do wonders. Well cooked kidney and liver are divine. Even so, it takes a master to turn brains into something I relish.
But this peasant thing! Seriously, not eating beautiful food because you think it will label your origins as being 'declasse' is precisely what makes someone, well, you know where this is going...