Why do current video games contain much more violence than they did in the past

Violence?Video consoles in the past didn't have the graphical capabilities to display "photo-realistic" graphics, so developers didn't focus on realism nearly as much as they do today. However, there were games in the past that featured violence, such as Mortal Kombat or Street Fighter. The violence was not nearly as pronounced due to graphical limitations (i.e you can't have blood splattering on the screen) but I'm sure developers would have included features like that if it were feasible. Many see the Video Game industry becoming mainstream as a cause of the "new" violence in games, but I believe the violence was always there, it just never sold as well.