Root's double ton came in winning cause. It is a pretty absurd claim to read that it doesn't count because in last 10 years, opposition team has managed to beat India in a test match only 4 times. India, on other hand have won like 30 times. Additionally, his 100 in Ranchi Test came on a tough pitch.
The runs Younis got in Sydney, neither the conditions were tough to bat nor did he changed the consequence of the game let alone the series. He has hardly done much in Australia outside of that, skipped tough away tours around 2009-10. He could barely help Pakistan save a test match in Australia let alone win it.
Pakistan pitches are flat and Root not scoring basically means he failed to cash on there because he has scored a lot of runs in tough conditions and as lone warrior, whether in England,India, Sri Lanka, South Africa, New Zealand, UAE everywhere except Australia. Failing in one country is a pass. Ponting also failed in India.