There is, or used to be, some show on I think the History Channel about how a lot of these processed foods are made. It was fascinating and disgusting in equal measures.
I think the real difference is that in one case you have someone watching a puree of HFCS, artificial thickeners, and almost-real-food slide down an assembly line following directions with little room for personal initiative, and in the other case you have people painstakingly writing code line by line, having to think carefully about each of them. There are a lot of people involved in manufacturing, but there isn't much thought and care compared to individual craftsmanship.
It's much cheaper to manufacture copies of software than it is to manufacture copies of oreos. It might make more sense comparing the individual who painstakingly crafts each line of code to the individual who painstakingly crafts each line of the recipe, the fabrication process, the machines that cook the oreos, and so on.
I think the real difference is that in one case you have someone watching a puree of HFCS, artificial thickeners, and almost-real-food slide down an assembly line following directions with little room for personal initiative, and in the other case you have people painstakingly writing code line by line, having to think carefully about each of them. There are a lot of people involved in manufacturing, but there isn't much thought and care compared to individual craftsmanship.