people can just keep doing it just to rile you up.  It is so cheap (low cost) to get reactions from China to reinforce a negative image of China.  Forget about spending billions on media propaganda.  Just spend a few millions on creating a narrative and trigger China to reinforce the narrative.

If Xi  played it cool, In 2016, Tsai wouldn't be elected as the pro US Taiwanese president.  To cast China as a villain would have been so much harder with all that progress happening in China and the lifting of hundreds of millions of people out of poverty. 

Look at the chart below.  Everything started when Xi took over in 2008.  No doubt he did many great things but defintitely a disaster in PR.  The tennis player Peng Shuai fiasco would have been a non-issue but, you know... Xi's China being Xi's China, it blew up to be about the evil CCP detaining a "victim" because she outed a CCP official.