Though it's for different reasons, Trump is putting large numbers of people in camps himself, and we've seen plenty of evidence of systematic abuse, neglect, and dehumanization. It isn't surprising that he would be sympathetic to another leader who uses similar tactics (even if his advisors make him condemn it to keep up appearances). There's little reason to think he'd do anything different in Xi's position.

Edit: For the downvoters, I am not 'whatabout-ing' or trying to diminish these terrible crimes committed by China's government. But I think it's naive to expect any credible US-led action against it while the leader of the US is committing similar crimes on a lesser (but still massive) scale.