Simple, because even though it was NOT a joke, any attempt at making jokes about neutron bombing the United States is sick anyway.
More to the point, that was only one example, that site is full of that kind of crap ALL the time. Any effort to deny it is absurd.
I wonder if Ari Fleischer's Single Bullet Doctrine [link to washingtonpost.com] is applicable here. :)
http://slashdot.org/comments.pl?sid=71886&cid=6491985
I have seen much much worse in the past, I just don't care to sort back through any of it on your behalf. Go look at that same thread, there's some other reference to "fire-bombing" SCO headquarters. You probably think that is funny too.