Cornell gets credit/blame for initiating the rise of sliced apples, which has increased sales of apples, in this study.
That's just the tip of the iceberg. In our local Safeway, the amount of cooler space devoted to packaged salad green mixes has exploded, as has the number which my wife has bought in the last year. And what I thought was a temporary display of guacamole and other dips keyed to the Super Bowl stationed just inside the doors has mutated into a permanent display of packages of things like fresh pineapple chunks, etc.
In some ways the trend is good. I assume there's less waste of food; even ugly apples can yield good slices. I don't see people being as picky over the box of salad greens as they are over a head of lettuce. And possibly the location of waste in the food chain shifts, more at the processing plant, less at the store. It's convenient--the labor of cutting up a pineapple or making guacamole is centralized and more efficient than the ordinary househusband doing it. It saves shopping time--by standardizing (the academic "in" term is "commoditizing" the shopper needs only to grab a box.
In other ways the trend is bad.It increases the amount of packaging material which needs to be disposed of. It encourages consumption, leading to obesity. Tradeoffs everywhere.