Well, IP bans can be bothersome for a number of reasons. One, people can easily change their IP, or simply have a non-static IP, and it could end up banning someone else. Also, suppose someone from that household stumbled upon here and did act in a courteous and proper manner, then they should not have to pay the price.
Though it does seem to lack any deception, so perhaps his skin being as thick as a rhino is not the only similarity...
