The stolen booty was used to pay the Venetians for the taxi fare to the Middle East. They also had enough left over to hand some over to the pope, who then found it in his heart to forgive the attacks on Christians in Zara and Constantinople.
In the end, Venice made an even larger profit than they would have if they had made a non-stop to Jerusalem. Very little of what remained of the Crusading army ever made it to the Holy Land, and so did not accomplish what they originally set out to do.
But they — Venice, the Pope, and the Crusaders — did make some money, which in truth was high on each’s real list of objectives.
So much for religious zeal.