Kirk's participation in this movie WAS pretty meaningless. Nothing in that movie required Shatner/Kirk. Picard's helper could have been a generic redshirt.
Everything about Kirk's treatment in Generations was awful, except maybe the opening scene.
His death meant nothing to the plot. Had the bridge not collapsed, Soran is still stopped, which meant the sole purpose of Kirk in this movie was to die.
Why? Had Kirk lived, all he had to do was "ride off into the sunset." Add a scene where he finds out Spock, McCoy and Scotty are all still alive, and say he's off to reunite with his friends--maybe find a job in Starfleet, or go on his next adventure.
Then they could either use him again, or not. But knowing he was out there was all that was needed.