You can certainly talk about controversial social issues in America, you just have to be prepared for people to not like you.
I think you may be running into another facet of American culture and misinterpreting interactions through that lens. In America, you pick your tribe. If you don't like someone, don't hang out with them! Friendships tend to come and go based on your circumstances of the moment, and if they fade away, it's no big deal, you'll make new friends. While in China (and many other places in the world), you're born into a tribe, and people will make significant compromises to their individual happiness to maintain relationships. Many Asian families exhibit behavior that borders on child abuse by American standards and would result in a kid cutting that parent out of their life, while such a thing is basically unheard of in Chinese culture.
I've got one Chinese parent and my wife is full Taiwanese-American. This was an uncomfortable cultural difference for both of us to learn, and we still sometimes feel the loss of that social web. But American society makes more sense when you view relationships through the lens of "people only maintain them while it is mutually beneficial and fulfilling for both parties, and if one person doesn't feel like the relationship is worth it they'll end it, and so your actions better bring joy and fulfillment to those around you."