My office holds the old naturalization records for our county (meaning up to 1958). In the last two years, I have had several people contact me looking for the naturalization records of relatives who came to this country. They were seeking dual-citizenship. Two wanted dual-citizenship with Italy and one with Ireland. I don't know if the US recognizes it or not. Apparently it was Italy and Ireland asking for the documentation.
Personally, I don't see why someone shouldn't be allowed to purchase a little dacha on a lake somewhere for retirement (especially if it is unaffordable here), and I don't see how it would make one "unpatriotic." But then most people that do so wouldn't expect the U.S. Marines to come for them if they stub their toe.
As an aside, one of the possible penalties of dual citizenship is that I cannot claim U.S. protection in the second country's courts of law. In other words, if I am falsely arrested and thrown in jail, I cannot claim my U.S. Due Process rights were violated.