In the past, large cities would have 2 papers, one Dem and one Rep and everybody understood the bias.     Now the customer has to look for the bias.

It could be that large corporate media ownership, who's #1 corporate objective is 'investor return',  focuses on what sells papers/broadcast not public service for balanced information.  Media corporations are about marketing, leaning on style and likability, not high journalistic standards.  

Major media corporations are power players in national and international affairs.   They seldom risk upsetting that relationship.   They will chose money/power over stringent journalist standards much of the time.  

Looks like it's 'buyer beware' when it comes to media.   Honestly, most people prefer media that match's their own bias and won't look much farther.