Nothing eventful should ever have happened in Star Trek, because as demonstrated in the episodes "Assignment: Earth" and the film "The Voyage Home" Kirk and his crew can travel backward and forward in time with considerably more precision and reliability than the Doctor and his companions.
So, either Kirk is a passive bastard with no compassion, concern or sense of responsibility to his fellows or episodes like "Operation: Annihilate," "The Doomsday Machine" and "The Ultimate Computer" never took place - the Enterprise must have gone back in time and undone them.
So, either Kirk is a passive bastard with no compassion, concern or sense of responsibility to his fellows or episodes like "Operation: Annihilate," "The Doomsday Machine" and "The Ultimate Computer" never took place - the Enterprise must have gone back in time and undone them.