It is simply a matter of perception. If one perceives, for instance, evidence of government surveillance programs being abused, and chooses to censor this information, this is wrong and goes against the greater good of GNU/America.
Yes. Regardless of the content, GitHub violated our constitutional right to freedom of expression. Just because you don't like what someone is saying, that does not necessarily make it wrong or bad, they have just as much to offend you as you do to offend them. I would highly recommend anyone who is currently using GitHub to switch to another version control system, as GitHub is most likely reading your emails, censoring your search results, and selling your information to proprietary software companies like Apple and Microsoft.