Why do people make violent video games

A violent game tends to sell better. Most games are violent even junior games have some violence in it though generally Tinkerbell doesn't 'lose' a head. People like violence it's a well known fact so why make something completely non violent? It just deplete profit though of course racing is different. Producers are out to make profit and it's near impossible to remove all violence whilst still being fun again excluding racing and some puzzle games.