Having seen Marvel's Iron Fist on Netflix, I can understand why many reviewers disliked the way Danny Rand fought. However, if he was unable to truly be the Iron Fist because of his unresolved emotional issues, then his inability to fight with the skill expected of a superhero like Iron Fist in the comics makes sense.
That said, Danny Rand isn't the most sympathetic protagonist I've seen in the various Marvel series produced for Netflix. He isn't exactly stupid, but the plot imposes certain demands that make it difficult to characterize Rand as anybody but an immature, unstable man-child who should never have been permitted to wield the power of a dragon.
However, Rand's appearance in the second season of Luke Cage was that of somebody who has gotten his shit together and resolved his issues, so perhaps the next series of Iron Fist will give him some character development. He might have grown up a bit during The Defenders, as well.
Still, I can't help but wonder what the people in charge of casting were thinking. The whole whitewashing controversy could have been avoided, and better choices might have lent a greater sense of verisimilitude to the story.