Factual error: The United States conducted no nuclear tests in 1947 and conducted none in Nevada until 1951.
Other mistake: Shortly after Quark, Rom and Nog arrive on Earth in the 20th century, just after they are observed through the one-way glass by the Army officers, the Captain in the hat who enters the room with the man in the suit to interrogate the Ferengi is wearing his rank bars on his shirt collar horizontally, parallel to his collar. The two bars of an Army Captain's rank should be worn vertically.
Answer: Part of the answer is found in "The Search: Part II" (season 3 episode 2). The female changeling told Odo that "the urge to return home was implanted in your genetic makeup. So he hardly has a choice in that. But being a sentient, thinking being, he recognizes the atrocities that his people are behind and he can't condone their actions. So it's a matter of his conscious mind warring with his instinctual gestalt. But on a more general level, we all instinctually wish to be among people who are like us. No matter how much he may like and love those around him and feel that emotion returned, there are numerous aspects of his life and existence that absolutely nobody on DS9 can empathize with or understand. And that's not even to address the pure joy and acceptance that is brought by the Great Link.
Garlonuss ★