They're honestly giving the people what they want in the cheapest possible way, with crap science to back them up when anyone questions about whether they ought to be eating it.
"Oh, you don't like Froot Loops? Fine, we'll give you Frosted Flakes with whole grain goodness. Still not healthy? Here's some Kashi. It's great with skim milk. Or, even better, with soy milk. Everyone knows soy is good for you!"