The answer is that they have no plan and spurn the effort it takes to make and implement a plan. Therefore, Zimbabwe will perish as Starnsville perished once the 20th Century Motor Company was looted to extinction.
Of course, the UN and the World Bank will probably reward Mugabe's thugs with low interest loans and grants which will disappear into highly-placed pockets and Swiss banks rather than being invested in Zimbabwe's infrastructure. This will merely prolong Zimbabwe's death throes a little longer. Hillary would be proud -- now everybody left in Zimbabwe can starve equally (and soon).
You are partly correct. Most do not have a "plan", for that implies thinking ahead with some sort of abstract reasoning process. But, as for the leaders (Mugabe and his band of thugs), they have a very definite plan.
They have found a happy fact of reality.....there always seems to be new, green pastures just over the horizon to loot once they've exhausted the ones next door. In this case, the new pastures are your and my paycheck. Once they are done raping and pillaging their way through Zim's white farms, they plan on raping and pillaging their way through our pockets.....forever.