Most mainstream cat foods contain large amounts of carbohydrate. This is easy for most cats to digest, and seems to encourage them to eat lots. Therefore manufacturers like it, because cats eat it well and therefore it sells well. Some people would prefer to feed a more naturally balanced diet, and some foods are made with this in mind
The Ziwi, Orijen and Acana foods are quite new to us, so we have not had a huge amount of feedback about them so far. However they embrace the idea that a more natural, low carbohydrate diet should be good for cats.
A lot of people say that kibbled food is not "natural". I suppose no commercial cat foods are natural. Then again natural does not always equal good. It was entirely natural for people to get Smallpox, and entirely unnatural for that disease to be eradicated through vaccination, yet most people would be pretty clear about what was good or not. Going back to cat foods, I think that the cereal content of modern foods causes problems, but maybe we will notice other problems with some of the lower cereal foods too, once we have used them more. On the issue of palatability, most cats eat too much and are fatter than nature intended. If they are offered foods they do not like as much, they will eat less, often to their benefit. However, we feel sorry for them "not liking" their food, so give them something which will encourage them to eat more, even though that is often too much. The less appetising foods might well be better for them, but that seems rather harsh. Once cats have got used to a type of diet, they can be extremely reluctant to eat anything else, regardless of how healthy or suitable the original diet was. It is not an easy task to change a cat's eating habits. Then it might take a while afterwards to achieve the full benefit of a "better" diet.
I think there are many cats out there which seem to live long and healthy lives eating nothing but mainstream kibbled food. It cannot therefore be terrible, though it certainly is not beyond improvement. The low carbohydrate diets seem better to me, but they have not been assessed and evaluated yet in a properly independent and scientific manner.
Personally I would suggest using a variety of different low carbohydrate foods, not just one type, and this will have to take into account your cats' individual preferences. Feeding just dried diets is not ideal for some cats, though others seem to do fine on them. I think that it is best to include a reasonable proportion of moist food in your cat's diet, though it is obviously not as convenient for us.