Iron Fist is a spectacular failure.
There are a lot of different reasons for this. On a purely practical level, so much of the show disappoints. The cast are bland and forgettable. The dialogue is awful. The stunt work is pedestrian. The direction is sterile. The special effects work looks like it was lifted from the later nineties. The editing is jarring. The attempt to recreate foreign locales looks like something from nineties television. These are all very significant problems with the production, aspects that would be irritating on their own, but come together to create a larger problem.
However, the flaws with Iron Fist are even more fundamental than this. Iron Fist is a show with an interesting premise but a complete lack of ambition. The show has no sense of its own identity or direction, its very existence dictated by external factors. It is a series that exists simply because it must exist, not because the writing staff had something interesting to say or because Danny Rand was the perfect hero for this cultural moment. Iron Fist exists because there is a slot in the schedule that needs to be filled, and Iron Fist aspires to do nothing more than fill it.
This is perhaps the most severe problem with Iron Fist. It is not that the show is bad, although it is definitely bad. The unforgivable flaw with Iron Fist is that the show is boring.