Because you omitted the most important characteristic of fascism. The melding of State and Capital to further the interests of Capital

Fascism is just one of the many forms of authoritarianism

Fascism is defined by the destruction of capital in non-military sectors, the dominance of some sectors of capital over others (beyond as laid out in imperialism to the point of contravening the typical form of the dictatorship of capital)and imperialist policies like forced labor being directed inward to compensate for a decline of empire.

Given that DPRK has industrialized throughout its history, has taken steps to shrink its military expenditures in comparison to the rest of the economy, has no dictatorship of capital within the country, doesn't use slave labor and is a historically imperialized nation as opposed to a former imperial power, I do not see how you can define the DPRK as fascist.

Explain how that doesn’t describe North Korea.

They'll probably tell you the Supreme Leader was elected or something.