Besides the obvious scientific issues and the other ways it's impossible to ever happen. Would you live in Rapture if you could?
For those who don't know. In the Bioshock games (1 and 2, and DLC in infinite), Andrew Ryan builds an underwater city to escape the world in prevention for a nuclear war and the government collapse (Bioshock: Rapture novel).
For me, I could. I love the idea behind rapture. Andrew Ryan's ideology, even though highly unrealistic (as the novel/games show) area great in theory.