Pi feels that agnostics are weak, inable to move forward in life and have conviction. He believes that doubt should exist, but should be momentary, to be replaced by a decision. Atheists have belief, and have made a specific choice about what to believe. Agnostics, if they remain so, never will. Here is the quote from the book that covers it:
I'll be honest about it. It is not atheists who get stuck in my craw, but agnostics. Doubt is useful for a while. We must all pass through the garden of Gethsemane. If Christ played with doubt, so must we. If Christ spent an anguished night in prayer, if He burst out from the Cross, "My God, my God, why have you forsaken me?" then surely we are also permitted doubt. But we must move on. To choose doubt as a philosophy of life is akin to choosing immobility as a means of transportation.