Trump's core supporters represent a small but vocal faction in this country who have absolutely zero interest in living in a country with Democratic (with a big "D") leadership. Call it Obama's America for short. They'd rather see the country burn than see an emerging multi-ethnic, socially liberal, international American society. We're talking about 25-30% of the voting public.
There has also been an effort over on the Right over the past 30 years to delegitimize any governmental body or institution controlled by Democrats. For example, we've seen screeds against "liberal, activist judges," the Clinton impeachment, lock-step opposition to anything Obama proposed, that has culminated in the rise of a right-wing entertainment-media complex that has supplanted traditional news among that crowd.
For those core Trump supporters, it was never about Hillary's emails or local control of government versus control at a national level. It's about the changing face of the nation. They would rather see the country burn than see themselves lose the culture wars.
The reasons for Trump's victory are much more complex than that. These core Trump supporters alone could not get Trump elected, but the Right in America has been responsible for the delegitimization of our political institutions over the past few decades that has resulted in traditional Republicans completely losing control of their party. Has it been worth it? A lot of my Republican friends are torn on this issue, but these are people who didn't vote for Trump or who voted for him despite serious reservations.
When you go scorched-earth, you get to rule over exactly that: a country whose political institutions have been scorched to the ground.