Yes, I can appreciate that North Korea broke its promises. But what do you see is an alternative? Military action? Or diplomacy picking up from the Carter, Reagan, Bush I, Clinton, Bush II, and Obama administrations (until the death of Kim Jong Il). None of these presidents engaged in the saber rattling that is now a hallmark of the Trump administration.
If their respective administration's efforts to stop the North Koreans from developing a nuclear weapon are all seen as failures, then with 20:20 hindsight what would you have advocated then versus now? Bomb the shit out of them?
Good Morning Mr. Schmidt, I'm heartened to see you including all of the failed actors leading to the current scenario in which we find ourselves embroiled. Now we are getting somewhere... By not separating them out by party, the first step in the problem solving process has been taken. Now to answer your question... Sun Tzu - The Art of War - "The supreme art of war is to subdue the enemy without fighting." Also, "Secret operations are essential in war, upon them the army relies to make every move.". Though we don't have armies facing off in the field, these quotes are applicable. You see sabre rattling; but something behind the scenes occurred, causing the unprecedented action taken by the Chinese.
Suggesting diplomacy of the sort used by the six failures you listed is, by definition, insanity. A different approach, short of war, has been undertaken. It is in the best interest of our nation this approach succeed. President Trump was certainly not our first choice as executive, but that's academic. Undermining him cannot help and it's undeniable that a very foreseeable consequence of failure (of the new approach) could have devastating consequences, including but not limited too, war.