A citizen is a citizen. You don't create second class citizen, who can see their rights revoked at any time, whereas the other class never has to fear anything like that. That's basic democracy 101.
Citizenship obligations for multiple citizenship is quite interesting from a legal perspective. Some citizenship require taxation regardless of where one live, which makes it possible to have a requirement to pay taxation to multiple countries. Military service is also an other interesting aspect. Giving people with multiple citizenship more rights than people with single citizenship would naturally cause problems, and yet you don't want citizens with different rights as that would indeed create different classes of citizenship.
A person can also end up with one citizenship in a country that allows multiple citizenship, and one which does not, and the citizenship of the person then depend on which country is being asked.
You just mentioned multiple citizenship means multiple taxation... That's "more obligations", not "more rights". You are not making any sense.
>A person can also end up with one citizenship in a country that allows multiple citizenship, and one which does not, and the citizenship of the person then depend on which country is being asked.
...What? You don't make any sense. I know Japanese people who live in Switzerland. Switzerland accepts dual citizenship; Japan doesn't. The stricter country wins out, and they had to choose whether to be Swiss or Japanese, full stop.
If anything it's basic democracy that if 51% of the population demands someone is kicked out, they're kicked out, no matter how unjust.
Democracy means doing what is popular, not what is right.
You do know learning ancient Greek and Latin was standard education of any well-educated person at the time of the American and French revolutions, don't you? And thus that they were perfectly aware of your tidbit of information? And that they elected not to adopt it? Maybe they even wrote about it? Maybe, if you were curious enough, you could have made all this reasoning above by yourself and looked up their arguments and the decades of back-and-forth on the topic before going, today, October 2026, right at "aktchually, Athenian democracy had ostrakon" as if this was a recent discovery that rewrites everything we believe about Democracy?