I am totally opposed to dual citizenship. I definitely do not think that anyone should be voting in two different countries.
A friend of mine is an American, born and raised here. He applied for and received Irish citizenship. He got it because his father was Irish.
He has no interest in voting in Irish elections. He got it just because he likes to travel, and having an Irish passport makes it easy for him to travel throughout the EU.
That makes sense.
Nevertheless, I agree with you. The Founders made a mistake here. Either you’re an American or you’re a citizen of some other country. Pick one.