I felt like when asked, Pi told these men the truth...but they could not believe and handle the truth, so Pi made up the story of the humans surviving the storm, but replaced the animals with human characters.
This story was brutal because it had humans acting like animals..animals are just honestly what they are.. Wild animals just trying to survive. All instinct.
The 2 ship men, did not like this story either, so Pi told them, you decide, what story do you like best.
Pi in his heart knows the truth. He does not care what anyone else believes. HE can live with the truth.... His faith allows him to be secure. He cannot give this faith and truth to others, they also are free to believe what makes them feel better.
I hope this helps...