Some of it might be political ideaology, but I think there is systematic blackmail, bribery extortion, and payoffs throughout media, starting with the ownership of news outlets. If it would be honestly investigated, the corruption would be mind blowing.
I personally believe, although it is based on circumstantial evidence, that many in the media are involved in perverse practices.
It would not be surprising that they do not want these investigations to go any further because they would be exposed — and the darkness hates the light because the light exposes the evil.