I agree with you.
For that particular outcome, the developers could have crafted something more cohesive with the game's narrative, offering a rewarding experience beyond just a title and challenge.
Even without much insight into their creative process, the two letters found in the office during 'free play mode' provided a clear glimpse into their mindset. Sachinama, one of the game's creators, vividly described his conceptualization of the game, likening Karryn's Prison to a symbolic representation of fertilization, with Karryn as the egg and the inmates as the surrounding sperm.
This depiction suggests a focus more on Karryn's rebellious persona than on developing a nuanced storyline, especially concerning her relationship with Prince.
It would have been preferable to see a divergence in the ending, perhaps incorporating scenes with Karryn and Prince for a more fulfilling conclusion, akin to a 'Real Happy Ending.' And the possibility of Karryn choosing to remain in prison with the inmates could have provided a more satisfying and lustful resolution, aligning with the concept of a 'Happy ending' with deeper significance.