It is a conundrum and I cannot explain why only that it is what it is. Things don't always made sense or that can be placed into neat little glass jars. If people could predict what happened than Trump winning the presidency wouldn't have been 10,000 to 1 which is nearly the odds of successfully navigating through an asteroid field.
However the facts currently now remains true that there is a deep distrust in the Democratic party with exposure of DNC and MSM collusion not withstanding. One could say that at least the GOP is honest in the respect that while they laughed at a Trump candidacy GOP gave him that chance. The same CANNOT be said about Bernie Sanders and the DNC.