If kicked out of South Korea, the US will be the ultimate losers.
I don't know what you mean by being "kicked out", but we should not remain if we are not wanted or needed. Moreover, it is time that modern countries like South Korea take full responsibility for their own defense. They have been living on security welfare from the US for over 50 years.
South Korea has the world's 13th largest economy. The have a modern, well-equipped military, which should be more than a match for North Korea. The US can provide the nuclear deterrent. We don't need American tripwire troops on the Korean peninsula.