Simple reasons why this was a failure, which no one can dispute.

Rating: 4/10 (5 March 2019)

Sadly, the anticipation for this film was not rewarded in the least... Others have already written detailed reviews, so I will simply focus on 2 specific reasons, which made the film a failure:
1. Character assassination
Lets face it. Either the writers had no idea what to do with the characters, or they are simply bad at their job. A few examples:

Supreme Leader Snoke was presented as a major threat, he was extremely intriguing, his power seemed unbeatable and theories ran wild as to his identity. Not only did we not learn anything about him, but he was killed in the lamest way imaginable...
Luke Skywalker, our beloved Luke... He is a man who refused to give up on even the most evil man in the galaxy, Darth Vader. Not only did he not give up on him, he actually turned him back to the Light! Now that same man tried to murder his young nephew, because he might turn to the dark side, despite having done nothing wrong by then! Does that make any sense...?
Rey is a Mary Sue, I'm sorry but she is... Anakin and Kylo Ren were trained since children, Luke was trained by two great masters and still struggled on a long journey. Rey masters the Force in a few days time because what..? Because she is a woman...? Modern political correctness at its best here, no matter how much some people try to deny it...

2. Pacing and poor story
Really now, between us fans, who cares about the whole casino storyline? I get them showing it, but devoting half an hour on this..? And again, the climax of the film is two ships slowly chasing each other? Since we heard Mark Hamill would return, all we wanted to see was Luke duel someone, be that Snoke or Kylo Ren. Couldn't they at least give us that? Then the whole film was setting up Rey and Kylo somehow working together, only for that plot to go nowhere... It was like a sad fanfiction...
Conclusion
Ultimately the film was simply not engaging... The pacing was way off, the story was full of holes, beloved characters were altered beyond recognition or swept aside to make room for useless characters like the Asian sidekick and none of the characters are given enough of a strong backstory to make you invested in their future...
The Last Jedi was a soulless movie that simply carried the Star Wars name, but that's not enough. At this point they will need a true miracle to turn things around in Episode IX.. Truly a shame what they did with a beloved franchise, but that's what happens when you let political agendas dictate...