Even Generations itself doesn't know what Generations' message actually is. Especially in regards to what it is that Kirk wants most from life/death/retirement. That one seems to change from scene to scene. Knowing Kirk it sure as hell ain't making eggs in a log cabin.
Oh come on, "Generations" conveys it's message just fine. To paraphrase;
Everything comes to an end, don't dwell on it and enjoy the hand you're dealt while you've got it.
It's not some obscure hidden meaning, it's blatantly spelled out for the less astute of us at the end of the movie. Even 12 year old me could decipher that when I first saw it.
Within the context of the movie nobody cares about Kirk. He's not the protagonist, and Star Trek fans can't seem to get past that. The movie is about Picard, Kirk was only present to act as the wise old sage who can help Picard learn his lesson of the day.
There are real criticisms to be leveled at Generations, but that's not one of them.