Their idea is to point out curing agents, flavor enhancers and similar stuff you would not need if using fresh food made from high quality ingredients - basically if you see food with these ingredients, chances are high that corners were cut along the path for whatever reason.

And colorants/"food dyes" are even worse. A bunch of them are under strong suspicion of being carcinogenic, and often are used to mask the ingredients being cured for longer shelf lives or being of sub-par quality.