Black Christmas is a lazily made film. There is no art to it at all.
The writing is terrible. As is common with lower quality horror movies, the film mostly reuses elements from popular horror films. The plot is a slightly dressed up version of Halloween, with a houseful of bitchy sorority sisters as the target of the psychopaths' rage. Characterization is done by direct exposition and reference to archetypes. And right when you think it's over there's one more "scare." It's all terrible and terribly lazy.
Of course, the most attractive woman is the one who lives.
Don't watch this ever.