Why is my cat always so angry?

Sometimes a cat or dog can get more aggressive when they are not feeling well. You have not said whether your cat has always been "ornery", or if this is relatively new. Because she is not actually responding to some sort of action on your part, it seems more likely that she may be experiencing some sort of pain or problem. A visit to the vet may be in order to determine whether she is having some health issue. Perhaps she has some sort of infection, or other health problem. Your vet can run tests, or at least check for excessive white blood cells which may point to some sort of infection. Does she also urinate outside her litter box? In this case she could have a bladder infection. Either way, take her to the vet and get their opinion. Other than that, try to give her extra attention, play with her, take little strings and pull them across the floor for her to play with, etc. - after you have taken her to the vet and they tell you whether she is healthy or not.