In short, Trump attempted to "offer" the same-old bargaining position the US has peddled for years. His senior staff told him he was wasting his time.
"Trump disagreed," the article notes. "He had taken to showing what he called Kim Jong-un’s 'beautiful letters' to visitors to the Oval Office, as evidence he had built a rapport with one of the world’s most brutal dictators. While some in the White House worried Mr. Trump was being played, the president seemed entranced — even declaring 'we fell in love.'"
Isn't that just dreamy?
This is also noteworthy: "Trump’s failed gambit was the culmination of two years of threats, hubris and misjudgment on both sides. Trump entered office convinced he could intimidate the man he liked to call 'Little Rocket Man' with tough talk and sanctions, then abruptly took the opposite tack, overruling his aides and personalizing the diplomacy."
Bottom line: Trump listened to his instincts, and his instincts didn't have a fucking clue. This is yet more proof of why Trump is spectacularly unfit to serve as President.