to skirt - "to avoid (something controversial, difficult, etc.)" (Webster's New World Dictionary) In this sense, “skirt” is sometimes used in the expression “to skirt the issue.” For example, “The two men kept talking about irrelevant things in order to skirt the issue.” From the viewer's impressions, perhaps the difference between amorality and immorality is not defined, or the two things are deliberately mixed with each other. Maybe immorality (or deliberate evil) is confused with amorality (the absence of the awareness of good and evil), or the idea of amorality is used as an excuse to promote immorality. In any case, the sentence seems to mean that the viewer thinks that Wilder films avoid a sharp distinction between the two ideas.

Thanks Sean. It seems the film is made to deliberately manipulate the viewer's perception so that it could have a dramatic effect.

It means that the film is deliberately unclear as to whether it has an amoral view/perspective or immoral perspective. In order to challenge the viewer to think about this.