Marketing. The manufacturers want you to believe their product is superior to the natural breast milk that they make zero money on where as it has been shown that babies raised on mostly breast milk or synthetic milk for babies have shown good results. I worked in the oil and chemical industry for many years and when the Jiffy Lubes, Oil Can Henry's etc. started coming into market they started telling consumers they needed to have their oil changed every 3,000 miles where as a car can easily go to 5,000 miles as long as quality oil and filter are used, but then the oil companies would sell less oil and the quick change shops will do less oil changes meaning big loss in profit. Corporate America at its finest.