Nobody enjoys thinking about the pain and torment happening around them, humans naturally want to be happy and see good things. Entertainment often makes people happy and helps people to forget about bad things. That being said, it can also convey themes directly relating to the pain and torment people in the world experience. While it doesn't usually make us happy to think about it, it's still entertaining.
I think media has always been used to influence the massses. A truth even present in antiquity.
I don't know if its intentionally used to distract us, but it does and without a doubt, there are those in power who capitalize on that very fact. If you had billions at stake? Wouldn't you?
In general and throughout history, entertainment has defaulted to a leisure activity done aside from everyday tasks. The field of people that fall under the category of "distracted" by entertainment are children and people who have a surplus of money and time, everyone else needs to pay attention to the real world. Otherwise, they would not be able to sustain themselves.
Although many children follow the dream of becoming an actor/actress, very few complete their journey; the vast majority are reigned back into a more worldly position. Those who do become famous and have a major position in entertaining usually have even stronger ties and opinions to society's happenings.