Trump's now trapped in his own two-part tactic of shoot from the lip (no scripting) and say outlandish things in order to capture the news cycle.
He knows he dare not pivot and be too presidential because then this happens: things like this Washington Post article in which policy comparisons with Hillary and his use of a script become the news stories, and neither of those topics help him...or, for that matter, sustain media ad revenue or media consumers interest in him at current levels.
This says more about We The People and the media than it says about Trump.
Most voters don't care about policy or policy comparisons. The majority of US voters reject policy-related news as boring. Instead, long ago (by media standards), they rated more highly reality TV content or content shaped by some distinctive reality TV characteristics, specifically individuals having an attitude, being outlandish, or having a strong "personal brand."
I reject the notion that the GOP alone created Trump. The USA created Trump. The majority did it by voting with their traceable, measurable media consumption of dreck tailored to short attention spans, and the media—which is a for-profit enterprise, remember—would be foolish to not curate at least some content in that direction.
Trump facilitates that incredibly well and has done so throughout this presidential campaign cycle.
The media in turn have given him $3 billion in free coverage.
It may not be as literal of a quid pro quo as that, of course. Trump was outlandish in previous presidential campaigns, too, but got little press coverage. However, the electorate has changed, Trump's refined his tactic, and, most importantly I think, Barack Obama isn't the other candidate this time around.
That's why the consensus that Hillary is a boring candidate is a great asset to her now in a way it wasn't when she ran against Obama. Obama wasn't throwing rhetorical bombs. He was often inspirational. In fact, Hillary tended to get notable coverage especially in those rare moments when she was provocative, deliberately or otherwise, like her May 2008 gaffe, “We all remember Bobby Kennedy was assassinated in June in California.”
Hillary will get less coverage than Trump unless her detractors keep successfully cooking up conspiracy theories and banging on about her e-mails in ways that manage to sustain the media's attention. But the sort of coverage born of Hillary's own statements, policy proposals, and whatnot isn't going to offend nearly as many people nearly as much as Trump's coverage will, because he's like to remain a verbal bomb-thrower and a peddler in burn-down-the-house fantasies that everyone's corrupt but him and he can wholly and remarkably remake government.
If Trump turns away from such a style, the race becomes for most Americans one of Boring Candidate vs. Boring Candidate, and in that climate, Hillary will almost certainly win the news cycles because then her presidential demeanor, gender, more in-depth policy proposals, and qualifications stand out more.
Of course, Trump and conservative PACs have been remarkably successful in the past in turning a candidate's apparent assets into liabilities. I'm sure they'll find new ways all of the time to make Hillary's experience, gender, in-depth policy proposals, and qualifications be evidence for why voters should be worried about the prospect of her becoming president.
In general, Trump knows he can't afford to be boring, so he figures he might as well at least pander to his base, and pray to the ghost of William Randolph Hearst for some sort of September or October surprise that will help him, hurt Hillary, or both.
What Hillary should fear most is something that so far seems unlikely: Trump starts to actually seem presidential and she somehow comes to be seen as less so. It's possible—everything's possible. And some massive Hillary gaffe or if she hugely mishandles some unexpected situation could occur and make her standing in the polls drop significantly. But, all things being as they are now, she's set to endure a wickedly negative, divisive presidential race, and a very close popular vote result, and emerge not unscathed but victorious.