I am veering into dangerous territory here but how does the holocaust differ from a genocide? They both are systematic ways of killing something you seem undesirable such as the Armenian genocide or the killing of Chinese by the Japanese.
So why isn’t called Armenian holocaust ? Does the holocaust only refer to the systematic killing of Jews?
This is reaffirms @Pirk explanation and also tells why the holocaust is called the holocaust. So the systematic murder of Jews is called the holocaust.