premise a LOT like the T Z zone episode "On thursday we leave for home".
The premise of a group of people stranded in some remote civilization for a long period--and suddenly having the opportunity to be rescued--is NOT unique to this movie.
It was done before on the twilight zone--one of the hour long episodes--"on Thursday we leave for home? on That one--a group of people are stranded on some asteroid or such, A very long distance from Earth. They have been there for many years and births and deaths there are common. They continually seek rescue with a makeshift transmitter outfit...but it never is responded to.
Till one day...and a rescue ship DOES arrive.
At first...EVERYONE is elated...even the leader of the group. Everyone is looking forward to going back "home". But as a short time passes...The leader discovers that people want to go their seperate ways once they get to Earth. He does not want this....and tried to talk people into staying. He is so used to his "supreme authority position" ...he cannot bear it to change. he even makes an attempt to sabotage the spacecraft--to prevent it from taking off, but is unsucessful. Eventually ALL decide to return to Earth...excpet the leader. He stays behind...imagining all is "still as it was...then had second thoughts as the ship departs..but is too late and left behind...forever.
A similar thing happens here...in this movie. After over 40 years a bunch of people living under the ocean on a sunken ship finally are able to be rescued..and the leader of those people--a man who was mostly responsible for their survival..does not want them to leave. He even goes so far--as to make sure th ship will implode on them all--killing them all instantly.