As a half-Korean who would not have been born unless my dad were stationed there...I agree!
But I don't want China/Russia in their current anti-American, authoritarian incantations to benefit so much. It would be nice that Korea - a 'united' Korea no less, remain an ally and pro-American in its orientation even without a U.S. troop presence.
Everything humanly possible that America and American blood and resources can do to make that happen has been done....and more.
Not to be harsh-but-5+ decades of coddling, protection, favor and hand-holding (often to our detriment) is ample!