You are wrong the Chinese won no matter how India benefited from the loss. That is the same sh*t people try to push here in the states when they talk about the crusades, they say oh the crusaders got owned BUT they got spices and learned how to clean their ***** so it benefited them and focus on that aspect while refusing to just put it bluntly that it was a military and diplomatic blunder on the part of the Europeans but I digress.
Now let us talk about Arunachal Pradesh what is the importance of this region? At first glance it seems none really but then you see the amount of resources in that land and you realize what the real issue is. Now in 1962 the Chinese practically over ran all the Indian North East and the question is why? Was it the ineptness of the Indian Army? The answer is no, although the Indian army was overly under prepared their training, equipment, and desire to fight had no real affect on the outcome of that war. Even if they were prepared for the Chinese invasion they would have been overrun. Now Indians will say but how can this be? The answer is pretty simple, it is called geography. North East India is easy to attack and hard to defend (do not ask me why go look this up for yourself). That is why the Chinese overran the area so easily. Now the second question is if they had captured the land they claim belongs to them why did they vacate this said land so quickly? Now this has to do with a variety of reasons. First one must understand what was going on in the rest of the world at the time, the US and USSR were embroiled in the Cuban Missile Crisis and Mao Zedong (the genius that he was) used this to his full advantage. Knowing that the US would not just stand around if the largest democracy on the planet was overrun especially by a communist army Mao waited for the perfect moment to strike. That moment was the Cuban Missile Crisis and so he struck when the US/USSR were preoccupied. Now why did he fall back after achieving most of his objectives?? The CBC had just ended and the US was willing to listen to Nehru who argued for direct intervention to save India, to which the US decided to just send supplies. Mao saw this so he relented and removed his forces from NE India but kept Aksai Chin. If India had won they would have pressed to continue the war but Nehru was desperate to end the fighting by that time. The reason why India didn't make much of a fuss initially that the Chinese kept Aksai Chin was that they knew it was barren and they were right on that part BUT the strategic importance of this barren land was overlooked. Aksai Chin gives the Chinese the high ground and advantage in any future conflict against India.
In the future should a war ever erupt they can roll down they armored division straight into IOK followed by New Delhi itself and then Mumbai to boot. Sure Indian Armour would put up a fight but it is much easier to fight going downhill than fighting an enemy coming down on you from higher ground (for obvious reason). The nuclear card is the only thing that keeps an aggressive China at bay from India as there is no telling what is the red line for India before they go nuclear (even though they claim no first use if New Delhi was about to be overrun I am sure they would reconsider).
In conclusion China won, Mao was a strategic genius (although a psycho murderer but that is another story for a different thread), and life goes on.