What are the elderly South Koreans going to do ? Go to their hospitals, hire them to take care of the garden ?

South Koreans are effectively banned from taking positions that deviate very much from certain state lines. The state suppresses "sympathy" with the DPRK or its party, reading any books from the DPRK, discussion of certain histories out of line with the state, including the history of Japanese colonization and Korean comfort women, and media are widely censored.

The official state line is that the South wants "reunification", but as described it is really the South taking over the entire peninsula. This maximalist position gained steam after the fall of the USSR, when the US instituted harsh sanctions and eliminated their primary trading partner, turning the North, which had previously economically outperformed the South, into a depression with fuel and food scarcity. This is where mean-spirited jokes about poor North Koreans come from. It can be challenging to get accurate ideas of the sentiments of average South Koreans due to the censorship laws but historically the wider public has wanted a peaceful reunification, including the proposal of the DPRK to have one country with two systems. This has been repeatedly rejected by the ROK state.