I think that most (painting with a wide brush) folks on forums don't actually care about punching down or up. If it aligns with someone they agree it's hahahaha without any criticism allowed. In this case, retarded has been drilled into their heads as some dirty word and the mere utterance stirs them up. But making fun of a sexualized child star going through a very real and public breakdown, nah that's cool.
One idiot in here actually told me to punch up with no irony.
This isn't just a critique of this place. The Internet in general is a terrible place to expect the vast majority of people to consider what they say. My sarcasm and pointing it out only sitrs the pot.