There are cultural and national behaviors and practices in Tibet that are expected by the populace. Same in every country. Tibet has it's problems.
Mainly poordom because strictly religous or philosophical peoples either follow practices that counter wealth gain, or just merely don't desire it,
such as in Tibetan bhudism.
I don't know much about the political structure or general atmosphere of Tibet, but I'm willing to bet citizenship is not like serfdom. I would
like some links or references please subz. Not that I don't believe you, just want to learn.

If the Tebetans are oprressed now, I would also
wager the cause to be on the Chinese.
The basic jist of bhudism is to reach enlightenment. The philosphy lays out some guides and practices to help in the path to that enlightenment.
Reincarnation is a strong belief in that you continue to live on earth until you reach that enlightenment. If I remember correctly, I don't even
think Bhuda himself made it there. Maybe he was the only one. Bhuda is not a god by the way.