K’un Lun is a notable void at the heart of Iron Fist, even before the closing moments of Dragon Plays With Fire.
There are any number of terrible mistakes that were made during the production of Iron Fist, fundamental flaws that could easily have been avoided by a more competent and committed creative team. The series was assigned a showrunner with a horrific track record. The production team cast a lead actor without any raw charisma and who was incapable of doing his own stunts, while refusing to put the character in a mask. The series focused more on board room antics than kung fu fun. The Hand were used as the primary antagonist.
However, one of the most grating disappointments is the simple fact that a lot of the really fun and interesting stuff about Danny Rand happens long before he stumbles back into New York in Snow Gives Way. There is a solid argument to be made that Danny Rand is a third- or fourth-tier comic book character, but there undeniable cool parts of the Iron Fist mythos. None of them take place in the offices of Rand Industries. Iron Fist is the story of a man who gained his power by punching a dragon in a heart. Whatever an adaptation of Iron Fist should be, it should never be boring.
And, yet, for whatever reason, the first season of Iron Fist makes a point to consciously shoot around the more impressive and distinctive parts of the Iron Fist mythos, reducing its title character to a cut-rate (and ironically trust-fund) Matt Murdock. Danny left K’un Lun behind, and it was a terrible mistake.