I actually think there's a lot to like about Nemesis
. Shinzon is an intriguing adversary who has a stronger relationship with the protagonist than any other Trek movie villain (despite nominally being a clone, he's more of a surrogate son for Picard from a dramatic standpoint), and whose story allows for some classic Trekkish exploration of philosophical questions: How much of our identity is destined by our birth and how much is shaped by our choices and experiences? Are good and evil intrinsic or learned? I also think there's some nice political nuance with the Romulans and Remans, multilayered intrigue and betrayal that feels rather Roman and unsurprising from the writer of Gladiator
. If nothing else, I was pleased to see the Romulan Star Empire actually depicted as an empire, i.e. a state that had subject races, which was a refreshing departure from the monoracial "empires" Trek usually gives us.
I think its weaknesses have more to do with the intrinsic conventions of Hollywood feature films that undermine good storytelling, like the emphasis on gratuitous action in SF films and the demand for relentless pacing. The biggest flaw of the film is that a vital dialogue scene between Picard and Data, one that sets up character and thematic arcs that are fundamental to the story, was cut out altogether because it was "too slow," whereas the completely pointless and problematical dune-buggy chase was left in to meet a quota for action. And those decisions fall on the director, editor, and producer, not on Logan.
The problem with the way feature films are done in Hollywood is that the writers have essentially no power, unless they're also producing or directing. The credited screenwriter for a film may have very little actual input into the final version of the script, or may be just one of numerous contributors. Writers are generally seen as just hired contractors brought in to assemble the story the director or producer wants to tell. So having a given writer's name on a screenplay is no guarantee that its quality will be at all consistent with other films credited to the same screenwriter.
Which is hard for most people to understand, for good reason. In most media, the writer is who you look to. In books, the writer's almost 100 percent responsible for the content, with guidance and mediation by the editor. In comics, it's usually a collaboration of writer and artist, though sometimes the artist contributes more to the story than you might think. In TV, the writers are the producers, the showrunners, the final decision-makers. So Hollywood features are the odd medium out -- the one where the writers have the least importance to the final product.
Although I'm hoping maybe that could start to change, since it seems some writers are becoming more influential in the game. Joss Whedon can now write his own ticket in Hollywood. TV writer-producers like Whedon, J.J. Abrams, Damon Lindelof, Alex Kurtzman, Roberto Orci, Zack Stentz, and Ashley Miller are becoming feature producers or directors. DC and Marvel have big multimedia divisions that are under the creative control of writers like Geoff Johns; 20th Century Fox has hired Mark Millar to be the creative head of their Marvel movie strategy. Hopefully in time the rest of the industry will come around and give screenwriters more influence.