The problem with the current state of unpredictability is that the trust and good faith which previously underpinned the actions of the authorities has been stripped away.
When you have a politician ranting to a mob that Muslims and Mexicans won't be allowed in and they get elected, that has consequences. All the actions that have in the past been dismissed as unrepresentative are being held up as representative examples.
The idea of a security concern that only happens to affect specific airlines flying specific routes is rather difficult for me to accept. When it turns out that the only two governments to impose the restrictions just so happen to have a commercial interest in establishing a non tariff barrier to protect their own hub airports against competition, one does ask if security is merely being used as a pretext for a measure designed to protect trade interests, not people.
The system of international relationships and connections depends on trust. I for one do not see any reason to give any politician the benefit of the doubt when I am taking them at their word.
What is said, cannot be unsaid. There are very good reasons why politicians with long experience in the system do not attempt to gain office using the methods that characterized 2016. It is one thing to gain office, quite another to gain power.