Re: No more future stories about Time Travel as a plot device - opinio
Well ... I wouldn't say it worked well in Generations.
Putting that example up against those Greg mentioned doesn't do much to balance the equation.
As for First Contact, the Enterprise episode, "Regeneration" seems to indicate that when the Ent-E left 21st century Earth...These are some of the potential logic gaps in time travel stories that make them problematic, if overused.
Who cares? "First Contact" is a really good movie regardless of what might or might have been done well in a later story.
Yet, even by introducing time travel in that film, as a weapon used by the Borg, the writers create a problematic plot tool. If the Borg can travel back in time to assimilate worlds in the distant past, at points in their history where they are unable to resist, why wouldn't they be doing that with every world they try to assimilate? Just open a time vortex, travel back, and take over the world. Sure, Picard and crew stop the Borg by the end of the movie, and first contact is achieved between Earth and Vulcan, but what's to keep the Borg from not just going back in time over and over again until they finally win? That's the problem with time travel as a plot line.
(Heck, if the Borg have time travel, why didn't they just send their thousands of invading Borg cubes in the Star Trek Destiny trilogy back in time to Earth's Stone Age, and just take over back then?)
So, yes, Trek has done some great time travel stories over the years, but as a plot device, it creates the problem that there is the potential to lose the suspense, because essentially, any action can be undone through time travel...
For example, when I first watched Generations, and saw the crew of the crashed Ent-D being killed on Veridian III when the Nexus hit and destroyed the planet, I felt no shock or suspense whatsoever, because I knew Picard would somehow reset the timeline by the end of the movie. Even in ST IX, I wasn't really shocked when Vulcan was destroyed, because the writers can always bring it back in some future movie, through time travel ... so time travel as a science fiction plot tool kind of ruins some of the emotional stakes in a plot, in my opinion.