First, to keep up our morale. If we were told the truth, many of us would have headed back into the woods.
Second, to confuse the deep state into thinking some bigger plan was at play here.
I'm sure Sessions did some stuff of value, but that John Dowd interview was withering about what a worthless AJ Sessions was.
Yes, not everyone was aware of the plan, but it's quite damning. Sessions would't even get on board with the border problems.
But that said, POTUS is dealing with real people with real alternative agendas. New blockers can appear.
I trust & have always trusted the plan, but lets face reality here, Mueller was a huge mess and derailed stuff for a long time. We all felt that delay on some level.
For all of us that struggled with how this just seemed endless, you have Mueller to thank.