Asides from whiny "TLJ is shit because my theories are all wrong" comments, I realize how most people are disappointed with the movie because the plot did not pay off, how the characters always made stupid decisions. What they failed to realize was, that's the WHOLE POINT of the movie. The theme of the movie is the inevitability of FAILURE. We are all bound to make mistakes when we are desperate and when we overestimate ourselves. Because at the end of the day, nobody is perfect not even the most powerful Jedi in the galaxy, Luke Skywalker. We all grow from our failures. Just like what Master Yoda said in the movie "Our greatest teacher, failure that is."
Right at the beginning, we all witnessed Poe disobeying his superior, Leia's order because he desperately wanted to destroy one dreadnought. As a result, his rash decision had costed many lives of his Resistance comrades. Poe is a man who obviously thinks very highly of himself which can be seen throughout the movie. When Poe was demoted by Leia, he didn't feel a sense of remorse at all but instead he was angry. Poe didn't learn from his mistake, he remained the same person as before. So, he repeated the same mistake of disobeying his superior which in this case was Admiral Holdo for the same exact reason. You may argue that Holdo should had told Poe the plan but the thing is Holdo wasn't obliged to reveal her plan especially to a man who had just costed many lives of the Resistance army with his poor decision. When Leia revealed Holdo's plan to Poe, that was the moment when Poe had realized his mistakes. At the end of the movie, Poe instructed his fleet fighters to flee instead of sacrificing themselves to defend the Rebel Base. He had finally let go of his pride. He learned to value the lives of his comrades over the glory of a hero. That's a brilliant character arc right there.
I can go on with this for the other characters such as Finn and Rose getting tricked by DJ which led to 'pointless' casino scene because they only trusted him out of desperation. DJ wasn't even the codebreaker Maz mentioned! Luke failed Ben Solo and his other students because he overestimated himself as a legendary Jedi master. Snoke got sliced in half because he was too arrogant to see that Kylo Ren wanted to kill him not Rey. Kylo Ren failed to gain Rey's trust because he thought Rey who was a nobody somehow understood him better than his own parents and Luke. Rey failed to turn Kylo Ren into the Light Side because she overestimated the good in Kylo Ren. I would love to go in details with all the characters arc but it's better if you rewatch the movie again. All the characters arc aligned very well with the movie theme.
Star Wars movies have always been about the chosen one being the only hope to save the entirely galaxy. That is what I love about the new sequel trilogy. It's the complete opposite of the previous trilogies. Everyone can a hero, everyone is a hope to the galaxy. A hero shouldn't be someone with special bloodline, a hero can just be a nobody who is willing to rise from every fall he takes.