I adore good, healthy food, well made, with good ingredients and at as low a price as can be.
I use as much home-grown, organic, natural, wild & local seasonal produce as I can, but there are so many things that are best left to the experts or simply impossible to make.
The point is, just because it came from a can or jar, it isn't necessarily bad. Food has always been preserved & traded, the modern era means that the quality, consistency and prices are better than ever.
While supermarkets have played their part in introducing and making foods more accessible I think that they are equally as responsible for many ills in society.
Over-regulation of farming means that you often don't get exactly what you think you are. "Standardisation" of Milk & the Animals bred for meat, sheep dipping, genetic modification, pesticides, deforestation and fertilisers are all major concerns worldwide.
We are generally blessed with an abundance of diverse and high quality food here in England, arguably more-so than some of our European cousins due to our colonial history.
You just have to shop smart & know where to find it all!