I don't get people that are trying to argue about definitions of free speech - there are enough of those to go around. Rather than try and consider others' arguments in the best interpretation possible, people seem to prefer to argue over whatever definition they are thinking about.
Nobody is arguing that you shouldn't be able to be criticized for whatever you say, since that is obviously a form of censor, so let's stop with the strawmanning.
What I believe the issue is, is that it's not the consumer that decides in this case - most people paying to read this wouldn't really stop reading something that they enjoy simply because of who the author is. They are reading this for their own enjoyment, not because of who the author is as a person. It's the company publishing this that took it upon themselves to decide for their readers that this shouldn't be read by said readers (in their defence - it was done under pressure from the Chinese side, still doesn't change the gist of the idea that it's not the consumer that makes the decision with his wallet), which in an ideal scenario is simply not their job. They are indirectly pushing their opinions and views on to the readers based on the fact that they are simply big enough to afford to do this.
People wouldn't have been outraged if the work didn't sell and it got axed, because that would have been a decision purely motivated by profit. In this case, there's obviously something more to the whole story. And while the publisher has the legal right to discontinue this based on whatever, it doesn't make the whole thing any more justifiable.
Freedom of expression goes only as far as the forums where one can make use of that freedom allowing it. The publisher in this case seems to be able to simply make it impossible for the author to publish his work.
I hope this clarifies why people are pissed - it's because it's thinly veiled censor at work. Nobody would be outraged if this was a business decision based on sales only. And while I believe that this manga is shit, and that it's no great loss that it got axed, it's still disheartening seeing underhanded practices being employed. Who knows, maybe tomorrow something of actual value would get cancelled on similar grounds.