All of post-conquest Tibet's land belongs to the "Chinese people". Since 99.5 per cent of the Chinese population is composed of Han Chinese, this means 99.5% of Tibet's land belongs non-Tibetans. (Although in reality, 100% of the land in China belongs to Communist Party cadres, no matter what your land title might say - the title can be canceled without notice, or appeal). I think the Tibetans were quiescent for decades because the communists let them continue living on their ancestral lands, even though these lands now theoretically belong to the people (i.e. the local party cadres, for the duration of their tenures). As Moose Dung Mao Zedong used to say, a single spark can start a prairie fire.
In Tibet, that spark was large scale land confiscations.
Han Chinese comprise 91.9% of the population of China.