It seems to me that Berman wasn't a very powerful movie producer. He got so much shit thrown at him by the studio, do this, do that. Generations was basically the attempt to connect plot points required by Paramount. Insurrection and Nemesis suffered from too much intervention by Stewart and Spiner. Stuart Baird directed Nemesis only because of some flimsy horse-trading with Paramount, and Logan got to write the script because Spiner did him a favor.
I don't know if stuff like this happened during the production of the TOS movies. Except for The Final Frontier, when Shatner got the job, and Paramount lost faith in the film, and then threw shit at him as well. Paramount could have gotten ILM for the effects and Sean Connery as Sybok, but no, it had
to be at the same time as Indiana Jones and the Last Crusade (also a Paramount movie).