Oooh, I bet you found those on a real credible website. Evidence Based Veterinary Medicine anyone?
Actually my opinions come from working with one of the top vets in the country at one of the top vet schools in the country. He's the one that calls it 'science death'. But they are simply my opinions. I started doing my own research after my dogs issues and watching other animals on these diets in my 8 or so years of veterinary experience. My own vets here at home have stopped stocking it after prescribing it for years because the animals were doing so poorly on it. I encourage you to do some research on proper nutrition and then start looking at the ingredients/nutritional facts of science diet and prescription foods. You can draw your own conclusion.
Another big problem is how hard it is to find the good kibble/dry foods. I have horses and am lucky that my feed store stocks a lot of the very excellent brands such as Taste of The Wild and Wellness Core (one of my dogs has a grain allergy and it can be tough to find grain free kibble). The average dog owner never goes into stores like this so their options are pretty much limited to the poor quality foods since they simply don't know where or what to look for.
I'll let the ingredient lists speak for themselves though:
TOTW:
Bison, venison, lamb meal, chicken meal, egg product, sweet potatoes, peas, potatoes, canola oil, roasted bison, roasted venison, natural flavor, tomato pomace, ocean fish meal, salt, choline chloride, dried chicory root, tomatoes, blueberries, raspberries, yucca schidigera extract, dried fermentation products of Enterococcus faecium, Lactobacillus acidophilus, Lactobacillus casei and Lactobacillus plantarum, dried Trichoderma longibrachiatum fermentation extract, vitamin E supplement, iron proteinate, zinc proteinate, copper proteinate, ferrous sulfate, zinc sulfate, copper sulfate, potassium iodide, thiamine mononitrate (vitamin B1), manganese proteinate, manganous oxide, ascorbic acid, vitamin A supplement, biotin, calcium pantothenate, manganese sulfate, sodium selenite, pyridoxine hydrochloride (vitamin B6), vitamin B12 supplement, riboflavin (vitamin B2), vitamin D supplement, folic acid
Prescription Diet:
Ground Whole Grain Corn, Pork Fat (preserved with mixed tocopherols and citric acid), Chicken By-Product Meal, Soybean Meal, Corn Gluten Meal, Soybean Mill Run, Chicken Liver Flavor, Calcium Sulfate, Soybean Oil, Flaxseed, Iodized Salt, L-Lysine, vitamins (L-Ascorbyl-2-Polyphosphate (source of vitamin C), Vitamin E Supplement, Niacin, Thiamine Mononitrate, Vitamin A Supplement, Calcium Pantothenate, Biotin, Vitamin B12 Supplement, Pyridoxine Hydrochloride, Riboflavin, Folic Acid, Vitamin D3 Supplement), Choline Chloride, Dicalcium Phosphate, Vitamin E Supplement, Taurine, Potassium Chloride, minerals (Ferrous Sulfate, Zinc Oxide, Copper Sulfate, Manganous Oxide, Calcium Iodate, Sodium Selenite), preserved with Mixed Tocopherols & Citric Acid, Beta-Carotene, Rosemary Extract.