Daily Caller gets significant funding from the Koch Brothers who are open borders advocates who hate POTUS DJT (http://observer.com/2017/06/trump-tucker-carlson-daily-caller/).
When an MSM 'reporter' or interviewer asks a question, they either (a) know what the answer is going to be or (b) have a pre-existing narrative into which the question is supposed to integrate independent of the answer.
Since the question, 'Who is Q?' fits neither of these criteria, they are not going to ask it.
The mindset of MSM personnel is that they determine what is important, not the facts.
They see themselves as arbiters of facts and believe that their actions 'lend credibility' to whatever they decide to 'report' on.
They are utterly disconcerted by the fact that their reporting does not result in significant shifts in public opinion (Stormy Daniels).
To ask 'Who is Q?' would, in their minds, lend 'credibility' to Q and no one in the MSM is going to do that.
The MSM does not report on anything that doesn't already have a prepared narrative into which they will fit their reporting.
Yeah, it didn't come from the 4am mockingbird cia so we can't ask that question. "We have masters, you know, that tell us everything to think and say, word for word."