"Then you know why I don't make the choice to ally with you, even if we want the same things. Even if we both want to see this edifice of lies reduced to fetid, moldering rubble. Choose me, mark me, or throw me away, whatever you do, I do not accept it. I am mine."

Roraschach is not a stupid man. He knows he has no real power here. He knows his words likely will impact nothing Tower does here, that they are, in every practical sense, meaningless. But words are important to him. They are all he has - he is a walking dead man, the memory of someone who once was, preserved in amber. If he is not true to that, to his own will, then he is nothing.