No one can logically compare the Iran and NK nuclear programs, because Iran and NK are dissimilar. And both pro and anti Trump posters make those comparisons. NK really is an anomaly among nations, in terms of leadership and how leadership is selected, economics and markets and the basic goal of it's decision making. You just can't compare the effect of intl sanctions, or the difficulty of getting them and keeping them on the two nations.
But Trump wanted "the summit" for a photoop after his shutdown. He got good optics he thought from the first one.
Donald Trump sees Kim Jong Un summit as TV ratings gold, wanted it as distraction from government shutdown: Report
Trump wanted the recent summit even though negotiators had no deal on sanctions relief or even what denuclearization meant.
Imo Trump deserves a bit of credit for not making a bad deal just to make a deal, which his advisors had feared he might do. And Trump met with Kim, and talking to a potential adversary is never a bad thing. NK seemed a little confused over what Trump said about ending sanctions, and Trump seemed a little confused over what NK meant by ending sanctions. But communication is a good thing, and Trump may have advanced the ball a little bit.