Despite what the carebear brigade thinks, the overwhelming majority of PvPers aren't gankers. The biggest PvP groups in the game spend most of their time going after eachother or organizing PvP events. The only exceptions to this is when a major event is going on (see Distant Worlds/Salome/etc) and the top few want to continue their reputations as being the Galaxy's super villains.
So yes, if the change is rolled back, the vast majority of people currently engaging in the massacres will indeed go back to PvPing among themselves.
Most random "ganks" that happen are by unaffiliated people who never post anywhere, the occasional anti-PvP player who gets the urge to try it themselves without telling anybody because they feel guilty, people who are just gasp playing the game they paid for in the way they want to, and a small handful of people who set out to be as notorious as possible.
Ah, the carebear brigade. Who do you incluide in that group? Is this the people sending death threats? Is it people who just enjoy playing the game solo?
I can speak, as someone who prefers PvE in ED to PvP, that I do not believe that the majority of PvPers are gankers. Likewise, i'm fully aware that some gankers are also compent PvPers, and can hold their own against competent opponents.
It doesn't change the fact that it is ganking happens, and those who are pushing this particular point about killing people until this change is reverted, are gankers already, and will continue to be gankers afterwards.