Why is China doing censorship?

Because revealing the truth is about the end of the government.

Why?

Because corruption is so widespread that a proper justification will put most leadership to jail. No one in the communist party can afford to do this.

Being a little poorer is way better then going to jail ...

Even if there is a way out of this, there are still problems though.

Many Chinese are conditioned to agree everything the government says. They never voted (not even be taught about voting), never expressed opinions freely (great firewall), never enjoyed basic human rights (forced marriage years ago, and forced abortion up till now), repeatedly abused by the changing policies with no power to fight back (forced retirement with little pension), out lawed (cultural revolution), threatened (everything can be a national security) and even killed (Tiananmen protest).

There's also a group of so called nationalist, but from my observation, it's more or less a show, since many are hired speak persons, they do this professionally. Poor job, all they do is talk shit. I do see hard core nationalist that are so brain washed to wanting to "protect China" at all cost and are eagerly willing to push the trigger to fire their missiles to Taiwan without any hesitation, they are just like that.

Those who enjoy their special privileges are usually associated with either the government itself or the state owned companies, there's no incentive for them to lose their current status.

And there are people who are just pure evil, the dark side of evolution.

While trying to break down this frickin' firewall, Microsoft, Cisco and those who help the government disrespecting human rights, stop fucking us!