I almost sort of almost agree with GrimJim (even though I can only read what you all quoted as he's been in my 'kill file' for a long time now), and I know many won't agree with me on this, it's a failing I have at explaining this philosophy perhaps, but I feel I have to try

.
It's really very simple moral stance I have taken.
1) Real life is 'PVP tag on 100% of the time'. Does that give you the right to kill any other human being any time you want? The arguements that turning it on implies consent is flawed for this reason.
2) When there was a cold war, which some of us may not recall, there was an 'enemy', it was people in the Soviet Union. However, I thought long and hard about this, and if ever I met someone from there, I chose NOT to kill them, as morally I had no reason to do so unprovoked. Just because you see someone from the other faction tagged, you are not morally right for just killing them.
I acknowledge that turning it on implies that I MAY be attacked at any time, mabye even without provocation, however, I also believe firmly that those who simply attack me 'because they can due to my tag' may still be able to 'gank' (which is a term for cheap kill imho), and may not be thinking clearly all the way through.
I have got miffed a couple times, but really, I have had the tag on since it was rolled out and it is always on, I don't cry over getting attacked unprovoked, but I do not kill afk crafters or anyone else 'just cause i can'.
I may get into it with someone i have a legit beef with or who has ganked in the past, but _THAT_ in my opion is consent.. not jsut simply being marked 'kiillable' by a game mechanic.
Cheers,