Students complain about explicit nature of course content

Today the dean reached out to me stating that several students have approached administration, filing a complaint against me and my course.

I teach an introduction to film course with lectures titled "Cinema and Ideology" and "The Male Gaze". The nature of the subject necessitates that we cover some Marx and Freud. Naturally, this includes discussing castration, queer theory, penii, and the desire to make love to one's mother. 

The dean has asked me to issue a formal apology, but that would mean bowing to the demands of the students. The dean has asked me to revise my course, to be more cautious with what I discuss. I feel that censoring my syllabus, however, would be unfair to the other students.

I have a second full-time job as a consultant at a tech company, am a credited screenwriter and producer. I teach out of sheer passion for the subject.

I informed the dean of my suspicions that the complaints may be related to the low marks on students' first essays. The dean suggested offering bonus tasks, but due to my job, I would not have the time to grade them, nor do I believe students should be offered such opportunities. They will not learn to write proper essays overnight.

Now, because of a handful of ingrates, I am seriously considering quitting this gig.

This is the first time that I have received such reprimands. How does one professionally deal with such matters?

EDIT: I usually invite several guest lecturers from the film industry every semester. After complaining to my director friend he offered to change the subject of his guest lecture from composition theory to the importance of sex scenes, cinema and the sexual revolution, and why it is important that we resist the decline of sex scenes in cinema.