Maybe because getting more than one perspective on life is always a good idea. I've learnt a lot having lived in both the UK and HK (about the good and bad aspects of both), have no regrets, but will likely move back to the UK one day.
How would you even know which is better if you didn't try both?
If you think of the world and your options as static rather than dynamic your mind is.. erm.. paved with shit?