Your logic becomes flawed when you realize how many % of the world's open source projects are hosted primarily on Github.
Their actions are all legal and good, and since I don't live in America, the freedom of speech argument is invalid to me.
That doesn't make this sort or action OK, and should in fact be cause for alarm.
To quote my favorite comedian, Steve Hughes: "What offends me may not offend you. And you want to make laws about this? How do you make a law about offending people? How do you make it an offense to offend people? Being offended is subjective. It has everything to do with you as an individual or a collective, or a group or a society or a community. Your moral conditioning, your religious beliefs. What offends me may not offend you. And you want to make laws about this? I’m offended when I see boy bands for god sake!"