Considering the CIA connections to his father, it wouldn't surprise me. I'm sure the numbers of people getting daily exposure to him has dropped since he's having to operate independently. After fame comes the, "what if they quit talking about me?" fear. Meeting masses in-person is far more effective at getting fans than any electronic marketing he could do. Besides, if there's merch to sell at an event, there's bank to be made. 

 His reach has increased not decreased. Fox viewership is tiny compared to prime placement on Twitter. 

 I don't trust platform data. Besides, increased reach does not necessarily mean a greater income.