Most of the people who whine about censorship don't know the difference between censorship and editorship. Censorship, which is what Hitchens described, is when the government (i.e. Austria) uses its force to compel you not to say a certain thing anytime, anywhere. It effectively says, "This alternative idea is not permitted anywhere within the country," under penalty of loss of liberty and property.
Editorship is simply the management of one single organ of communication, for purposes that may include (but are not limited to) disapprobation of an idea. An editor is not a censor anymore than a being ejected from a restaurant by its manager is equivalent to forcing you to starve. Your use of someone else's edited resource to facilitate your speech is a tacit agreement to the terms by which that facilitation is offered. If you do not agree to the terms, then you are quite free to find some other means of expression, or to create your own. An editor who disallows discussion of the Holocaust on her gardening blog is not running afoul of the First Amendment in the least bit, nor in any way standing upon morally shaky ground.