Not everyone using this site would recognise this command as extremely destructive, and a small but non-zero percentage of those people will probably run it just to see, under the assumption that the community is not out to sabotage them. This example is easy for an experienced *nix user to understand, but people will be posting more convoluted commands, whether as trolls or innocently. Next time might be a simple virus piped to Bash or a command to send your ~/.ssh/id_rsa or browser history to a chat channel, who knows.
I have added a comment to the question, but I feel like the command should instead be rendered harmless by replacing rm with echo and explaining why in the question itself, with a warning to not try this at home.