It's not the job of the media to "turn on every candidate" - that would imply the media favored certain candidates...What the media should - and in the past did - was know history, know the record of the candidates they interview, and not be afraid to challenge answers and not allow someone to dodge a question. I saw Ben Carson interviewed this morning - he dodged every question he didn't like, consequently Carson's interview amounted to him just repeating his campaign rhetoric. I also saw Carly Fiorina interviewed this morning - she too dodged questions she didn't like and the moderator, in this case Chuck Todd, just moved on.
FOX, as you say, is a different media outlet - they don't hide the fact that they're an arm of the GOP.
Frankly, there are very few real journalists around today - most are teleprompter readers who are not knowledgeable enough to challenge a candidate's answers/non-answers.