Nechomah – as you mentioned “in and out”. This is the time where governments need to make quick and simple rules that can be easily followed. We have similar ideas in halakha like “lo plug” – do not create rules that can be confusing. Are the current Israeli rules reasonable in general? they appear to be: there are lots of problems with people travelling inappropriately and it is in Israel’s interest to limit that. So, if your son chose to travel to another country during pandemic, he is taking the risk of being inconvenienced somewhere.
Citizenship is a well recognized concept that creates mutual obligations between state and a citizen. So, state is willing to go an extra mile for a citizen. It is great that there are organizations trying to help in such hard cases, but it is “chesed” you are asking for, there is no reason to complain about generally reasonable rules Israeli government is using to save lives. Try to think how you can help the situation rather than create more confusion.
PS I read a story about some American who went to see his sick mother in Australia, travelling through multiple PSR checks on the way. When he finally landed, he is waiting for hours for a bus that will take him to an isolated hotel. He text his Oz brother how annoyed he is. Brother replies – if you do this in your country, you would have done better ..