We all know PG-13 is box office gold compared to an R rating for movies like this. But what exactly is an "R" rated superhero?
According to the MPAA, the superhero resides in a film that "contains some adult material. An R-rated motion picture may include adult themes, adult activity, hard language, intense or persistent violence, sexually-oriented nudity, drug abuse or other elements, so that parents are counseled to take this rating very seriously."
http://www.mpaa.org/FlmRat_Ratings.asp (source)
As you see, it's not just language, it's HARD language which of course is unspecified. It's not just violence, but intense and persistent. Nor is it just nudity, i.e. "naked women", it's nudity presented in a sexually oriented nature, and it's not just using drugs, but abusing them.
And even after all that:
"Generally, it is not appropriate for parents to bring their young children with them to R-rated motion pictures," says the MPAA guidelines.
This is all entirely subjective and as a result most movies are not faithful to their source screenplay or origin book due to cuts and re-edits to satisfy the MPAA so the most revenue can be squeezed from the largest possible audience. What you end up seeing onscreen is the result of a board of 10-13 individuals, each working periodically, each with their own agendas under a chairperson who has unlimited power to select anyone they choose - the qualifications being no more or less than experience with parenthood as an adult member of the community. Film producers are also under no obligation to submit a film for rating, but the industry as a whole has learned an unrated film squashes advertising revenue, reduced media exposure and opens up the door to lawsuits and negative publicity from special interest groups. So they play the system, often re-submitting films over and over after copious edits to try to satisfy the MPAA for that "gold" PG-13 rating. Any industry member knows it's not about being faithful to their art, it's all about that rating and the resulting increased revenue.
And the MPAA site states, "No one in the movie industry has the authority or power to push the Board in any direction or otherwise influence it."
We all know that the public influences the MPAA, society influences it, and the constant pushing of the envelope by film producers clearly influences how ratings are classified and assigned to those who "volunteer" for the MPAA's stamp of approval. There is no alternative, so this is how the system works until the industry and society as a whole puts enough pressure on the MPAA to put their loose standards to the test.
Is this system as described above corrupt? You're damned right it is.