All Koreans hope for it to happen, especially those who aren't part of the very upper echelons of the DPRK. Just because folks live in DPRK and are bombarded with bullshit doesn't mean they aren't very well aware of what their realities are like when compared to that of the South.
Sneakernet is (was?) alive and well in DPRK and most of the population knows they're living nowhere near the levels that those in the South are. They just are fucking terrified of them and their families being killed by hard labor if they say otherwise.
So; sure; it's /possible/, but until something big changes, it won't happen. The only reason it's not actually happening is because of the humanitarian crisis it would create. No one wants to deal w/the fallout.
It wouldn't be just a humanitarian crisis but huge economical and social problem as well - suddenly this single country would be enlarged by ~26mln people who would need to be adjusted to life in a completely different reality, and who also would need to be secured in variety of ways.
The comparison to German unification that's often bring up seems to be accurate only on the surface. There are large differences like mainly the cult of personality created by the Kim family that affects life of people in NK. It's not possible to dismantle that day by day, and surely government which would had to deal with unification would also face resistance to some degree. This society has been for over 70 years conditioned to hate, looking for the causes of their own misfortune outside in the pure evil that USA in their eyes is and its puppet state of SK.
It won't be a 0-1 change where on Monday you attend annual parade where you worship Eternal President and Dear Leader, and by Tuesday you plan your first vacations on Jeju island.
Moreover, the situation in the end of 80s in Europe is the key factor - namely the domino effect started in Poland which spread across the whole eastern bloc. There was a strong opposition building up within societies of Central-Eastern Europe demanding changes and freedom. Pretty sure that's nearly non existent in NK - there's no trigger for large changes. Even the famine in the mid-90s wasn't enough.