Why shouldn't South Korea have nuclear bomb?

A lot of people are getting confused about South Korea. South Korea is a totally different country compared to North Korea. North Korea is as poor as Somalia, but they don't care whether or not, their people starve, and they put over 90 percent of their budget into their military. INSANE!! South Korea's gross domestic product is the world's top 12 and almost 50 times more than North Korea, and you guys know some brands from South Korea like Samsung, LG, Kia, and Hyundai. My point is they have the technologies and money to make nuclear bomb, but they can't even try to buy uranium because of the U.S. I am getting sick of watching North Korea doing something crazy and lunatic against South Korea. Let them have the bomb and bring our troops back from South Korea.I don't think South Korea will do something stupid with the bomb. I think they are rational and practical enough to handle the deadly weapon. Is there any reason South Korea must not make the bomb? I think North Korea already made it.