can you give me some information about this genre?
They depicted a morally questionable world where the heroes and villains oftentimes resembled each other closely than had previously been shown.
Revisionist Western
They depicted a morally questionable world where the heroes and villains oftentimes resembled each other (see antihero, sympathetic villain) more closely than had previously been shown. 
where was the movie the quick and the dead filmed Tucson, Arizona. what type of film is it? A revisionist western film.
wiki:12233589
Revisionist Western [SEP] Introduction
The Revisionist Western, Anti-Western or Post-Western is a subgenre of the Western film that traces its roots to the mid-1960s and early-1970s. Some post-Classical Hollywood Westerns began to question the ideals and style of the traditional Western. These Revisionist Westerns placed the context of the Native Americans and cowboys alike in a darker setting. They depicted a morally questionable world where the heroes and villains oftentimes resembled each other (see antihero, sympathetic villain) more closely than had previously been shown. The concept of right and wrong became blurred in a world where actions could no longer be said to be good or bad.