I don't know the answer either - or rather, I do, but I don't know how we get there from here. But for what it's worth: you have to be rich to afford the best of everything, but many of us are rich enough that the question becomes which things are worth paying the price for. Food in the UK is comparatively cheap, there's a lot of competition to be the cheapest (not just among the discounters but further upmarket too), and as you say, that cheapness tells us something about the quality of the food. But we put up with it because housing is expensive, and we have to make savings somewhere. So bad food subsidises the property market...