Because they did not. At best you could claim that they ran abit of a police state, which is inherently abusive, similar to how minorities in American cities are currently treated, but the difference is that China brings in work, and offers free work training with anti-radicalization and Maderain language courses. Not only that, but most of this was at the behest of traditional Uighur community leaders, whose institutions were the primary targets of radical Wahabi terror bombings. The target wasn't Uighurs or Muslims, but the specifically radicalized ideology coming out of Saudi Arabian funded Afghanistan/Pakistan groups.

Not only that, but the height of these programs was in 2012-2018, with the U.S. 'reporting' on it starting in earnest after the programs had already began to spool down. Reporting on it now is quite literally pulling a KONY2012.