You're never going to totally separate politics from the Olympics, but I don't think that's always a bad thing. Some things are more important than sport. If a unified hockey team is what it takes to help reconciliation between enemies and prevent nuclear war, hell I'm for it. People are people, you got to build a sense of trust and rapport before you can talk about the important stuff like weapons negotiations, and this seems like as good a place as any to start. Besides it's not like the South Korean team was a medal favorite powerhouse to begin with, what is there to lose?
If you were a South Korean player and getting a few minutes playing time on the ice was more important to you than the potential to ease international tension and improve your country's relations, I'd think you might want to reevaluate your priorities.