It is true that there is an increasing number of people preferring content showing violence and cruelty. In my opinion, there are myriad reasons for that with the most prominent being psycological factors.
First and foremost, content that exposes people to violence tend to evoke stronger emotions than any other type of entertainment. For instance, one study has shown that the heart rate of people watching a TV program about travelling was lower than that of people watching a crime film. Consequently, people get more adrenaline from witnessing cruelty than new locations. Thus, the lower level of emotional satisfaction render people more bored and make them search for the sources of strong emotions via watching violent scenes.
Secondly, constant exposure to violent content may render people more stress-resistant and less anxious. Violent shows rise the level of stress to such a high level, that real-life problems and inconveniences seem tiny and meaningless. Considering the study conducted by a British University, when 10 out of 20 pupils watched a movie with cruel scenes before a math test, it is evident that strong emotions achieved from watching violent shows help people outperform others. Notably, those 10 students who had not watched the movie were extremely focused on their feelings and a high level of anxiety. In comparison, people who had watched a movie outran the others, having been less conscious about their problems and feelings.
To summarise, there are many reasons for more people opting for vibrant and shocking shows. Some of them are in search of strong emotions which are rarely felt on daily bases, while others just want to switch focus from the mundane troubles. It is felt that the tendency is bound to continue with even more people exposed to violent content in the future.