The issue is that Trump's experience, is trying to run a business, which often ended in a complete failure, but it's obvious to everyone, that you can't run a country like it's your company, political diplomacy is a complete different animal than selling books and opening a terrible "university". A powerful company can easily "threaten" smaller partners into submission, with the lame tricks that Trump is trying to use in his presidency.
If anything, the world will hopefully learn that businessmen arent fit to run a country, anymore than politicians are fit to run a company, or a baseball player will be a successful racedriver.