Lets all be honest here. This is a legitimate complaint that needs room for improvement.
My guess is that Trump believed he could trust more people than he actually could not because of naivete but because this is government he is dealing with and not business people who have slightly more honor and loyalty.
I watched his interview with the Flashpoint guys, and he admitted this. Said that this time around he knows who the good guys are and who the bad guys are.
In business, you hire people to do a job. They either do it, or you fire them.
In government, people have their own agendas.