To the extent that for either to work you have to suspend your disbelief. The subtext of Life of Pi can be summarised in three lines:
1) Life is a story.
2) You can choose your story.
3) A story with God is the better story.
If you've read the book or seen the movie, you recognize this as not only a good summation of both but point three as being the final declaration of Pi to his interviewer, just not using those exact words. (If you have not read the book or seen the movie, you would be best served to do so without reading further as spoilers await) The problem is, not everyone thinks that way and allegories work best when they're more than an allegory, that is, when they could easily function as something not allegorical. No Country for Old Men, for example, can work as an allegory for many things or it can be taken at face value. Because it does not state its message or meaning every few minutes, it can be so much more than an allegory, it can also be a sober and somber tale of treachery and evil. Life of Pi, on the other hand, states its message with reckless abandon, points out its own symbols, and even identifies its own allegory as such in its final moments so as to let the characters, readers and/or viewers choose for themselves which made the better story (and if you didn't answer the one where a brutal and deranged Gerard Depardieu kills and eats a sailor, we clearly have different outlooks on life).
Of course, that's the point (that we all choose our own story) but it's weighted, heavily, towards the other story, the one with the animals. We see the tiger story over the course of an hour but we only hear the deranged Depardieu story over a total of about five minutes. When the choice is given, of which story is better, the deck has been relentlessly stacked.
I take comfort in reality and reason and Martel does not, as he points out thoroughly in this talk to be found here. That's fine and he's the author telling the story so he should absolutely stack it in his favor. But when he talks of children dying as a reason to have faith, i.e., to give their death a purpose, I can only think, having encountered such things in life, including a drowning, a fall to death from a bridge and a little girl of five cut up and stuffed in a closet, it is much more comforting to know there is no reason for it at all and no cosmic plan. If there were, I would be forever depressed, in bed and cursing existence. When he says, in the talk linked at the top of this paragraph...
And I remember thinking, if you are dying in your bed, you know, if your legs are like two little sticks and you have a mountain of a stomach and you’re rotted by disease, you know, you’re, the flesh on your face is melted away and you’ve lost your hair, what’s the point of being reasonable? Why not believe in whatever? You know, whatever? Jesus, Buddha, any one of these? Why not believe that someone transcendentally loves you? Why not believe that?... all I can think is, "Because then that means you have to believe that someone in control has chosen this horrible end for you. And now you have to die knowing that." Perhaps that is comforting for some but not for me. To me, that is hopelessly defeating. I have children and would never do anything to harm them so the thought that there may be a cosmic power that decided it's an important part of the plan to have this child raped and dismembered or that child drowned in the rough surf is one that makes me sick to my stomach. What evil would ever devise such a plan?
Life of Pi tells its story well but it takes the easy way out by not dealing with the nature of that cosmic plan. What it does, instead, is say, "Life can be brutal and violent but if you substitute animals for the reality, it's easier to take." That is, if you substitute a God story, it's easier to digest life. But that's not true once you introduce the plan where Anne Frank dies of typhus and children are shot dead in a school. Now the story becomes, "and there's a father figure that made this happen for a reason."
"So, wait," you ask, "you mean someone planned this out, someone who could have stopped it but didn't?"
Yes. And if that doesn't depress you, I don't know what will. I don't want to imagine that kind of evil, that kind of hopeless horror, planning out anything.
For me, the reality is more comforting. I'd rather know that my friend's cousin, raped and mutilated at five and stuffed in a closet, died because horrible things happen, not because she was playing a part in an all-important plan, a plan so callous and monstrous and without empathy that it, in fact, involved a five year old girl being raped and mutilated and stuffed in a closet. That plan is morally filthy beyond compare. I'd rather believe that we are here to make what we will of this world and when we pass, it will not be because some plan pre-destined it but simply because we died.
In the end, I much prefer the philosophy of Will Munny: "Deserve's got nothing to do with it."