My cynical opinion is that, unfortunately, "trump stories" == "clicks/viewers" == "more ad revenue", to the point where no news organization can afford to _not_ cover every ridiculous story about Trump.
No disagreement, I'm familiar enough with media revenue streams and what-not that I understand the "appeal" of coverage. It does kind of remind me a bit of the way media members 'covered' for Tiger Woods for all those years. As in, if you wanted access to him for interviews, content, etc, you'd better keep certain things out of print (so to speak). Skewering Trump would "curtail" access, or, more than likely, result in a lawsuit threat.