In perhaps no other industry are consumers focussed so heavily on paying the lowest price.  As a result, even the names of many food stores are based on price (Buy-low foods, Costco, Thrifties, SuperValu, Save-On Foods, etc.).  This single focus on price has caused even wealthy consumers to feel that they have to get a deal on their food.  I once read a research study from the US that reported that in 1980 only 20% of the wealthiest 20% of the population had every shopped at a deep discount store for food.  However, by the year 2010 over 80% of the wealthiest 20% of the population were regularly buying food at deep discount stores.

So long as consumers focus almost solely on price (often at the expense of nutrient quality), it will remain very difficult for food producers to earn enough money to be economically viable.