This is dangerously wrong.
Earlier this year, I noticed something in China that really surprised me. I realized I felt more comfortable discussing controversial ideas in Beijing than in San Francisco. I didn’t feel completely comfortable—this was China, after all—just more comfortable than at home.
There are many more unsayable things in Beijing than San Francisco, and the penalties for saying them are much harsher (though of course not for Sam, as a very wealthy foreigner most rules simply don't apply). People are regularly beaten, harassed and murdered for reporting the truth about the government in China. Journalism is a very dangerous profession there in ways it is not in the US.
http://edition.cnn.com/2017/12/14/asia/chinese-beat-korean-j...
https://cpj.org/2016/04/chinese-journalist-sentenced-to-near...
In contrast, the dangers Sam runs from being open are that people will be mean to him on the internet.
I am less worried that letting some people on the internet say things like “gay people are evil” is going to convince reasonable people that such a statement is true
This is a really odd statement of a non-problem which dismisses real world life-threatening problems a lot of marginalised people live with. First, reasonable people are not the problem, violent, irrational people who are influenced by bad ideas are. Second, this is not an academic debate over people with naughty ideas, real lives are ruined by the normalisation of bigotry and hatred (in ways that Sam in his privileged bubble has never and will never experience, and apparently can't even imagine). People are murdered, spat on and denigrated even at their funerals when hate like 'gay people are evil' is allowed to spread. Sometimes, to remain human, you have to choose a side.
This is uncomfortable, but it’s possible we have to allow people to say disparaging things about gay people if we want them to be able to say novel things about physics.
Why would those two things ever be related? Why can't we let people say novel things about physics, and call them out when they (for example) harass gay people, sexually assault people who work for them, or do other bad things. Why would we possibly want to excuse bad behaviour because someone comes up with novel physics ideas?
What sort of confusion of ideas could lead to linking these two topics?