There is such a thing as "protected speech" and speech that is not protected. Inciting to riot is one example of non protected speech as well as yelling fire in a theater, libeling others, disturbing the operation of a school and sedition. While it sounds rather noble to say all speech should be free it's a bit naive to really believe it.
You are free to criticise the govt. and that is what the first amendment was really about. The ability to make your grievances with the government heard by the government, not to belittle, denigrate, besmirch, or libel a fallen soldier and offend the family of the deceased service member during their funeral.