There's a fine line between these two ideas - that people should have freedom to write what they want but that they have a responsibility not to. I can more easily see, "People have the freedom to write what they want but not all writing has value."
If you say, "You have the freedom to do what you want but you have a responsibility not to exercise that freedom." If you have a responsibility not to exercise that freedom, then do you really have that freedom in the first place?
Admittedly, you have the freedom to choose not to fulfill responsibility, but the thought seems to me to violate the spirit of freedom. If you're truly dedicated to the concept of freedom, it's hard to believe in the responsibility portion.
Well if you're going to believe that, why not go all the way? As you see it, morality is the enemy of freedom, so why don't we all live immoral lives so as to exercise our "freedom" to the fullest?