Yes, this does affect my airline preference. I think it is appalling that customers are expected to pay so much for the flight itself and all the taxes. We should not have to pay extra for soft drinks, snacks, food in general, entertainment or the headphone required to take advantage of them.
Long airline flights can quickly become boring, and result in headaches, air sickness, and more. By providing passengers with free entertainment, airlines such as Delta offer distractions for people of all ages. This reduces boredom, allows the passengers to have something to focus on, and may reduce these instances of air sickness and headaches.
Delta offers free entertainment on their international flights, as do most airlines, including United and American, however on domestic flights, not very many of Delta's aircraft are equipped with free TVs. Airlines like Frontier provide free entertainment, and airlines like United have DirecTV available for purchase on most domestic flights.
I tend to find the entertainment very cheap and not the kind of thing I would normally watch. However when I'm there I have the urge to watch. I want to better myself so I avoid going on planes with entertainment. Same with the airplane food. I only go on planes where it costs a lot unless I'm going on long flights where I'll NEED food. So in a way I guess it does affect my airline preference
Delta's addition on free entertainment, while it is desirable, is not a considerable option for me. I try to take a straight flght between my current home and my parents home when I go for a visit. Only one company flies straight. To take Delta I would need to split into two flights, and that would be inconvenient for me.
It does not affect me at all whether or not there is free entertainment. It all comes down to price, if I can get a cheaper rate somewhere else that is where i would go. I can bring my own entertainment and save money that is what I would do.