I know it's only only "for" vegetarians. As I clarified, a wide variety of animals can eat it, but hay is primarily roughage fiber -- that is, grazing animals have been evolved to break it down effectively and get the few nutrients in it that are available (which is why rabbits and guinea pigs are cecotropes -- they literally have to digest it twice to manage any nutrients from it).No I was just saying hay is not only for vegetarians. Have you tried other cat foods or filler free small breed dog food? though the protein levels are different. Also apparently they make commercial chinchilla diets
For animals that aren't evolved to digest this nutrient poor roughage, it basically goes in one end and out the other. In terms of nutrition, you might as well be feeding them styrofoam.
I'm not sure why you're offended that people are contradicting your advice when you first admit you know nothing about hedgehogs. The chinchilla food you suggest is also primarily hay and not appropriate for hedgehogs.
Look at it this way, guinea pigs also need protein. You would never suggest feeding them cat food because it's full of meat -- which they aren't designed to digest. All protein, fiber, etc, is not created equal. People need fiber too but nobody is suggesting you chow down on hay.