Altzheimers is a problem.
Therefore, we say that there is a problem with their brain.
BUT NOT
There is a problem with their brain. Therefore altzheimers is a problem.
Alzheimer's is caused by a problem in the brain, one that is understood to an extent and different from what causes other problems. We label the effects of that cause "Alzheimer's."
Do you think we should label it something else? Or are you just against giving things names?
Do you reject that there are different types of diabetes that have different causes too?