Because there is no such thing as right-wing dictatorship.
There is only right wing, relative to other political positions. Fascism is rightwing to communism, for example.
However, when you run the gamut from communism to libertarianism, authoritarianism is only on the left side.
That was my thought as well. What would a “right-wing dictatorship” be? You freedom people to death or what? The government minds it’s own business and people eventually die from an unrequited yearning for Jack boots?
Nice explanation of what right wing is
Libertarians are socially leftists/atheists.