There are two reasons:
1. People who recognize the irony and are trying to piss you off.
2. People who think of ganking as perfectly normal and are just being respectful.
#2 is like the same deal when somebody messages me after a duel, "Why bow when you stunlock/wear MoM/spam parry/chain BS/whatever." Well to me those are totally normal things, so to me there's no reason not to bow.
1. People who recognize the irony and are trying to piss you off.
2. People who think of ganking as perfectly normal and are just being respectful.
#2 is like the same deal when somebody messages me after a duel, "Why bow when you stunlock/wear MoM/spam parry/chain BS/whatever." Well to me those are totally normal things, so to me there's no reason not to bow.