As others have already pointed out, it's the extraction and concentration of fructose (which is what is meant by "processing" in this context) that is so bad.

As others have already pointed out, it's the extraction and concentration of fructose (which is what is meant by "processing" in this context) that is so bad. The perfect example is that it's unlikely you'd have the appetite for eating 15 apples, but it's not difficult to drink 15 apples worth of juice.