Did you know the Dalai Lama is Marxist? He also wanted to reform Tibet before he fled from the country.
But we see a country with a different language, different script, different beliefs in many ways from the Chinese..
Whether or not Tibet historically was part of China politically or not doesn't change that, that it needs to find its own solution, and whether it continues to be politically part of China also is beside the point.
I think many Chinese don't appreciate that the demands of many of the Tibetans in exile are rather moderate. Basically just preservation of their culture and basic human rights.
I think the Chinese attitude to such demands which to we in the West anyway seem very moderate, speaks volumes.
The Chinese when they portray the Tibetans in exile as extremists are not credible, when you look at what the actual demands are, which are not extremist at all.
The Dalai Lama and Tibet Office have asked for reunification of Tibet into a single region within China with local self-rule, real autonomy to govern their own affairs within China, which again seem moderate demands to most of us as you can tell by the other answers here also. It's only the Chinese, for the most part, who see these demands as extreme. Hopefully this can change with greater mutual understanding.
Another thing that makes the Chinese statements that the Tibetans are extremists not too credible - nearly all the statements about how bad things were for the Tibetans before the Chinese invasion of Tibet and about how great things are for them now are by the Chinese.
If the ordinary Tibetans really did suffer greatly under the Tibetan rule as the Chinese claim - and if they really were happy to have been liberated by the Chinese you'd see posts here by people with Tibetan names saying these things, about how great things are under Chinese rule - not by people with Chinese names.
But instead the main things we hear from the Tibetans in Tibet themselves - on the news anyway - are protests against Chinese rule
Plus - we have examples of Tibetan culture outside of China and though not perfect by any means, they are certainly not places where you have slaves and serfs and extreme hardship for poor people.
Especially Bhutan which often comes up as one of the topmost happiest countries in the world (happiness more important than wealth in my view) - and is a religious country that still has Tibetan Buddhism as its main religion. And has changed slowly - towards a democracy in its case.
Tibet would take a different direction, presumably - and as a Buddhist myself I'd be interested to see what a Marxist Buddhist country (I mean of course as an autonomous region of China) is like since that seems to be the way they want to go.
Do you see how to Westerners what the Chinese say just doesn't seem to add up? I'm not doubting that Chinese citizens genuinely believe these things, but perhaps this might help explain why they are not widely believed outside of China as far as I can see?