In my opening statement, I told you a little bit about what happened in the 2010s when there was a turn to pious forms of Islam. The Chinese state viewed that turn towards more pious forms—and they're really just mainstream forms of Sunni Islam and Hanafi Islam—as the Talibanization of the Uighur population. They feared that the Uighurs were turning more and more towards Afghanistan and central Asia.
Then there were also a few violent incidents, one in Kunming where there was a knife attack that killed over 30 people. China refers to this as their 9/11. There were also some sorts of ISIS-style attacks using vehicles to run over populations of civilians in both Beijing and in Urumqi. People who were killed numbered in the tens, and in one case 30 or more. Also, the people who carried out those incidents were carrying black flags with Arabic inscriptions on them that seemed to indicate that they were doing some sort of Islamic act in carrying out those violent acts. China viewed those things as signs of terrorism arriving in the country, and they do meet the standard of what could be defined as terrorism.
The problem is really that they're conflating those who carried out those acts with the population as a whole, whereas most Uighurs have no desire—and had no desire—to carry out violent acts towards civilians, the police or the state. Instead, they just wanted to live their lives. They wanted to perform their faith. They wanted their children to have a better life. That was their primary concern. The state is not recognizing that.