There's a huge difference between media attacking the president and the president attacking the media. One is the watchdog function that was built into the first amendment, one of the fundamental principles that set the U.S.A. apart from monarchies and dictatorships. The other is a hallmark of monarchies and dictatorships. 

A president undermining credibility in the media is a step towards totalitarianism. It's typical of banana republics and cheap two-bit dictators. No president in modern history has behaved so badly. It's offensive to all Americans.