Once you understand the simple concepts behind fuzzy logic, it's easy to start thinking of the many, many ways in which it can be useful. In reality, it's just another tool in our belt, and each job requires different tools.
Fuzzy logic is great at taking some data; evaluating it in a way similar to how a human would (albeit in a much simpler way) and then translating the data back to information usable by the system.
Fuzzy logic controllers have several real-world use cases. Some are more obvious than others, and while these are by no means one-to-one comparisons to our usage in game AI, they serve to illustrate a point: