Yes, they did get support from other teammates as well, but we can not blame one person for the loss. Virat and Shami were impressive in this World Cup and led their respective stats. I still think that India was a better side in the World Cup final, but they did not execute their plans accordingly. Siraj was bowling beautifully with the new bowl, and in the final, out of nowhere, Rohit gave the new bowl to Shami, who was good with a slightly new bowl throughout the tournament. Siraj was ordinary with the old ball. Indian spinners hadn't taken any wickets either in the middle phase, which is the main reason for Indian defeat.
At the toss, Rohit was very clear about batting first, and he did put AUS bowlers under pressure, but after his wicket, Australia took charge.
On that day, the planning and execution of Australia were way better than that of India.