One word, dearie, - Unpredictability.
If you ever negotiated a billion dollar deal you'd know what the heck he is talking about. But you haven't, so you don't.
Yes, Donald is treating this like a deal negotiation too.
It has the fortuitous side effect of a larger “We The People” participation than the traditional campaigning of career politicians who try to sell the people into changing to suit them rather than negotiating some kind of accommodation, an accommodation which looks like it will go significantly conservative just because that is where “We The People” are with respect to America’s current governing class.
I see the people worrying that Donald will not live up to his deal. To that we should ask, what has Donald done before in deals? If Donald was dishonest enough, he wouldn’t be trusted to be able to make the kind of deals by which he turned millions into billions.
Unpredictability? That's what you want in a candidate? Wouldn't you rather like to know up front who your candidate really is and what he/she/it stands for?