The core issue is that the Chinese government locked someone up for stating an opinion. An opinion not much different in substance than then ones you are stating in this thread.
Would you consider it just for you to be imprisoned for your views alone? I would not, and I think that is also true for other people.
In most western democracies, you can be imprisoned for a multitude of "thought crimes" - denying the holocaust, inciting racial or religious hatred, encouraging acts of terrorism etc.
The US has uniquely strong protections for free speech, but even there I expect that many people would support a ban on certain kinds of speech. How many Fox News viewers believe that jihadi preachers should be locked up? How many New York Times readers believe that white supremacists should be locked up?
Would you consider it just for Assange to be under house arrest in an Embassy?
Would you consider it just for Liu Xiaobo to be under house arrest at his own home?
Well, IMHO, all 3 incidents are unjust. However, they all happened.
Interestingly, Liu Xiaobo earned a Nobel price, but Snowden didn't. Not sure what would happen if the Chinese government awarded Snowden or Assange some special prizes.
I don't agree with Snowden's treatment either, but it's important not to confuse freedom of speech with dissemination of confidential information.
1. Liu is not acceptable by a lot of Chinese people due to his aggressive words on colonial and slavers.
2. Liu was sentenced by the gov due to "subversion".
So to judge Liu, we have to look from at least two different angles, not just "he was sentenced".
Few people thinks 2 is right. I, personally, do not agree on 2 too.
And I am now thinking why most people outside China only know about 2 when they try to judge about Liu?
If he only expresses some views of his, it's probably OK if he's not influential. If he got awarded some prize that's important worldwide and sometimes awarded to POTUS, well, it's totally a different thing.
Would that alone be enough that I would ask him to be imprisoned? Never.
You're confusing a dislike of his opinions for justification for jailing him, yet again.
If you are interested in how he was jailed, search google, there are tons of articles there.
It's not a charge that means a lot to those educated in the west, who would probably view it as a thought crime charge.
Can you explain its use and value better?