Giving them a platform of technical equality with the United States was a huge giveaway to the Kim regime. His father and especially his grandfather dreamed of being seen as equals to the United States.
This dates back to the negotiations that created the DMZ at the end of the active phase of the Korean War.
Both Korean States were treated as the junior partners during the negotiation phase. The United Nations Command (aka the United States) and the PRC dominated the negotiations. North Korea and South Korea had very little say in how things played out.
South Korea wanted to continue the war until capitulation. North Korea, being the junior communist partner, wanted the war to end for a variety of reasons. But ultimately Kim Il Sung’s wishes were squashed in favor of the PRC position. They never negotiated with the UNC as equal partners.
The sit down was what Kim Il Sung always wanted. And we gave it to his grandson without any real guarantees that he’ll hold up his end of the bargain.