We don’t watch the news to get an uncriticial raw feed of the President’s own self-serving talking points. We can read his Twitter account and press releases, and watch his unedited press conferences, if we wanted that.
Journalists are trained to get to the bottom of a story and follow the facts wherever they lead.
If the truth turns out to be unfavorable to Trump, then the media has a responsibility and professional obligation to report it that way.
The alternative is press self-censorship.