This is a good observation but I have somewhat of different analysis to why he does this; a lot of it is shifty pretense when in fact he yields immense power in the KWP power structure and over the military—from what we know. For his age, KJU has been showing considerable aggressiveness in his leadership and he started with that early on (he learned political terror and leadership as an understudy of his father, KJI, over a five year period or so), then moved on to execute his uncle (execution), his brother (assassination hit), and purged nearly 250 military and party officials from his father’s day and advanced more loyal people to the leadership of the core (and corps).
The question is, are the people he’s eliminating for or against making overtures to the US, is Kim eliminating the hardliners, and maybe he doesn’t quite feel safe enough yet to pull the trigger?
Because we know Kim, even if he wanted to, couldn’t simply make a deal unless he knew the opposition to it is completely wiped out.
I don’t know yet what to think about it. Maybe Trump knows something we don’t.