To me, this makes the case of people that want real, imposed censorship weaker, because you can say, "Just block xxx and be done with it". With .com, they can say that someone needs to protect you because you might accidentally go to a bad .com website or something like that, so active filtration is needed. If .xxx becomes the standard and the .com just redirects, it will be easy for people who don't want porn to not get it, people who do want porn to get it, and people charged with filtration to relax a little bit.
Why is this bad? How does it strengthen the argument that the internet should be actively censored?