One thing that can be seen as a problem is the fact that not all foods have to be labelled under Australian law. For example, food items that are made at the place that they are sold need not be labelled. Therefore, a consumer going in to a bakery to buy a cake may not be able to determine what sorts of ingredients have gone into that cake.
A second issue could be that there is so much information on the packages of food that the actual meaning of the information may be difficult to discern. It may be that people with relatively little education and those who have not taken the time to learn a great deal about nutrition and health will not understand which foods are actually good for them and which are not. In other words, the labelling gives only factual information and does not interpret it well for consumers, telling them which foods are healthy and which are not.