It's just their government. The people are pretty okay (I lived in China for 5+ years).
Also, consider their neighbor, Taiwan, which is also "Chinese". If I remember correctly, the 9 Dash Line was originally an ROC thing and you don't see Taiwan pissing off every other country around them.
And if you see their post about it on Mastodon, the tone is kind of like "I guess we fixed this one already, nbd."