Well Australian conditions demand more physical & mental abilities than raw skills. That's why guys like Harbhajan Singh / Anil Kumble did well as compared to Ashwin. Whereas Ashwin can use the Indian Slow conditions to full effect through his skills.
Another thing if you observe Indians cannot throw (or at least not used to) from these long boundaries. Keeper/Bowler is not near the stumps to collect the balls, they rather move few yards away from stumps nearer to fielder to make it easy.
India has tough time in Australia and this World Cup. To compete in Australia you need full-fledged team in all departments (like Srinath/Zaheer in their prime, fighters like Harbhajan/Kumble, real destroyers like Sehwag, sheer talents like Ganguly/Dravid, legends like Sachin, etc. You cannot compete with forced inclusions like Akshar patel, Yadav in the playing 11. You need a full team)