Ethical sourcing is privilege, yes, and status as well.
That doesn't mean it's wrong.
Food in particular is a source for this controversy. Over the past fifty years, the population of the planet has doubled, but food cost as a proportion of the economy has halved. This is due to the techological advances of "green revolution" agriculture - tractors, transportation, and chemical fertilizers and pesticides. But there ain't no such thing as a free lunch. Cheap food comes at the price of health and environmental damage, among other things. (want slavery? Check out the chocolate supply chain.) And it's not a huge luxury to eat more ethical foods. Middle class people can afford it.
For the middle class, it requires you spend more money that you likely don't have on an intangible benefit that doesn't factor into your bottom line equation. Upper class folk will concern themselves with Davos-esque visioneering, societal progress, and "downshifting" as their free time and resources allow themselves to explore new ethical practices.
The true middle class is focusing on critical value trade offs (getting more for your money) and family unit stability. This narrows their energy away from the broader problems and closer to matters of survival. Consider how even Whole Foods or "Goop" is seen by your average middle class individual -- a spot for dilettantes to overpay for apples rather than a representation of hope for working farmers and healthy children.
I think the upper-class must steer away from the concerns of themselves and shoring up their wealth and towards a reinvestment on society, something the recession in the US and depots in Russia and China have set back as members now fear assets could disappear at any time. A portion of the super-class (Gates, Buffet etc) have already tried to evangelize this with some progress -- whilst facing opponents like the Kochs and others who seem to have a more socially adverse ideology.
Depends on where you live, maybe. Here in Minneapolis, quality food is a thing, not just for the rich, but for the middle class and even the poor. Sure, there are always tradeoffs, but we're not living on the McDonalds dollar menu and Maruchan Ramen - not if we can afford better, and most can.
The real cost of quality food isn't so much money as time. My daughter does most of the cooking for the household, because she loves it. She spends a couple of hours a day at it. I love to cook too, but I don't spend hours a day cooking, because it's not a good tradeoff in my life.
That doesn't mean it's wrong.
Food in particular is a source for this controversy. Over the past fifty years, the population of the planet has doubled, but food cost as a proportion of the economy has halved. This is due to the techological advances of "green revolution" agriculture - tractors, transportation, and chemical fertilizers and pesticides. But there ain't no such thing as a free lunch. Cheap food comes at the price of health and environmental damage, among other things. (want slavery? Check out the chocolate supply chain.) And it's not a huge luxury to eat more ethical foods. Middle class people can afford it.