The concept of cruelty is also being deliberately altered to appear to us to be more acceptable - and even sexually stimulating.
That is one of the reasons I have avoided slasher movies for the past couple decades. I remember an old episode of Siskel and Ebert when they said they refused to review a movie because it mixed sex and gore (the poster for the movie had a guys head with pins covering his whole head).
I see your quote above a bit differently. Marketing people see that certain things cause some kind of physiological excitment (blood, gore, sex), and that if certain levels of exitement are reached in one area, it is easier to arouse excitement in another.
Have you noticed how many movies show somebody vomiting (I'm squeemish, so I notice it a lot)? That causes an emotional reaction that then makes people more susceptible to experiencing other kinds of emotions, then the person thinks that the other parts of the movie were better than they otherwise would have been rated.
... this is the movie that Siskel and Ebert refused to review:
Yes those are very good points - The first that yes, there are certain things that tend to create a natural excitement that is exploited, without the awareness of the "viewers".
With regards to including certain scenes in order to prompt people to feel that the movie is better than they otherwise may have thought is a form of priming, a psychological term that can be explored a bit here: https://en.wikipedia.org/wiki/Priming_(psychology)
There is so much that takes place in our society that influences and impulses us on sub and unconscious levels. The more we start practicing an awareness of this being done, the more we can determine, with awareness, what does and what does not influence our thoughts, behaviour and words. Thank you for your comment :)