[bawolff]

I can understand the logical leap that people took to get there:

Most processed food in western diets are unhealthy for you. Usually because the processing basically means very high in sugar, and relatively low nutritionally. It doesn't take much to go from that data point to a rule of thumb "natural = good".

Especially if you combine it with a mistrust of large corporations that you believe prioritize profits over ethics (not exactly a huge leap) - where you think that the stuff they make is bad, but "natural" things they didn't have a hand in cant be corrupted by them.

Real life is much more complex than that, but i can see the chain of logic people use.