Really ? Do you openly discuss LGBT rights in Beijing ? What about rights of Uighur folks in China ? Do you discuss that in Beijing ? What about Tibetian rights ? Is that discussed ?
As long as you don't try to subvert the government or anything, you can talk about it.
Talking about it influences opinions, and when critical mass is reached, even autocratic governments sometimes are forced to abide by the consensus of their people.
Noone's claiming that China is a better or more progressive country btw, just that in this very specific regard, US is worse than China.