There are plenty of news stations on Cable tv and radio that focus are on more "serious" issues. For example: PBS, NPR, BBC, Al jezera. People definitely have choices, but the what gets the highest ratings? Sensationalized news, and Pop/Country music stations. What get's the highest views on Youtube? Again it's sensationalized news and Pop music.
If the big stations focused on whatever you consider to be priority issues, they would quickly go out of business. The stations are a reflection of their audiences. It's not the other way around like you suggest. The media companies make decisions based on focus groups and ratings statistics. I'm sure there is pressure from the Admistration and other Authorities as well. But what about YouTube? Is there some conspiracy out there that gave Gangnam style, Macklemore and Justin Bieber some of the highest viewed videos of all time?
Even on this site, this subforum is the least viewed and has the least active threads. Get it with reality here.
The average person would rather watch some thing exciting or funny than watch something about politics, science, business or any other topic that they struggle to understand. It's not the job of the media corporations to educate the masses. The media is supposed capitalize and profit from the aggregate wants and needs of the masses. There is no moral component here and there shouldn't be. PBS and NPR are non-profit entities so they have the luxury of playing whatever they want. While some NPR programs are very successful for the most of the day, nobody listens to NPR, and barely anyone watches PBS as compared to other stations. One doesn't even need a cable subscription or anything else (besides a TV) to watch PBS.