At least, a travel ban makes sense for many reasons.
There are bad people out there in the world and you also would not let bad people come to your home.
Yes it seems on first sight a judge about people who never did something bad and never would do it in future.
But if one people makes something bad, often other people would be hurted for it too.
If it is the german actor (Jasmin Tabatabai) who has passport of Germany and Iran, who can not travel to their family right now, just because she is born in Iran and came to germany when she was a kid.
Or if it is the militarian employee who has to stay on rooms, because one guy of his company made an bad mistake.
Or if it is the chilrdren who don't get sugar treats because her sister stole all from the cupboard even it was not allowed to take them.
Or just let all people of Salem block the way to Tier2 witches, because one of them was too greedy.
General punishments makes sense in communities to make them realize, that some things are not allowed.
But then you have to find a way to rehabilating innocent people and communicate this way.
To come back to the travel ban.
It can be a way to show the bad people, that it makes no sense to travel to the enemy and hurt them, because they don't want to be hurted.
And the innocent people will understand it, because they know why they want to go out of their countries and to find a safe place elsewhere. They know very well, that the posibility to travel is used by non innocent people and they are the first one who don't want to meet them in their choosed new home.
It might be hard on first sight, and i even say this as a very social thinking people, but on second sight it can be able to bring safety.