Reunification is generally seen as a good thing in Korea, and would, eventually, greatly boost the economy of Korea. North is so poor right now because they defaulted on all their international loans and investments in the 70s, basically scamming the entire world including USSR, then their reaction was to just withdraw internationally and focus on military with sadly high poverty and starvation rates, with a shit economy.
South Korea managed to do the opposite, and have tons of international success and prestige. If they could govern the other half of Korea, surely tons of companies will see the opportunity to start up new markets to millions of new people as an excellent investment.
Also to that idiot in this thread who doesn't understand the problem, its that North Korea has endless amounts of artillery pointed at Seoul. Any launch of hot, open hostilities between USA/SK and NK, North Korea would spend all of their resources trying to take Seoul. They have tunnels, transports, everything at the border to just bumrush the city, after they completely flatten it with nonstop artillery, missiles, naval bombardment. They will then occupy the capital city and try to engage USA forces in a guerilla, urban combat war in the middle of a massive population center where we simply can't "blow them all to hell with AC-10s like CoD lol." They will try to use it as negotiation leverage.
The result of this would be almost everyone in Seoul dying, or their lives ruined. 10 million people. 25 million metro area. One of the biggest cities in the world. Then everyone in Pyongyang would die if they don't capitulate.
North Korea's infrastructure will be blown to hell, and they certainly will not be a match to USA airpower and strategic flexibility, but the exact same can be said about Iraq, Afghanistan, Vietnam, etc. All wars we handled terribly. Unbelievable that people can still be so cocky and ignorant about war when literally every instance of war of this nature in the past 50 years was an incredible waste of life and usually strategic failures for countries like America.