To me, spawn killing is not using a game mechanic in an unintended way. The game mechanic is to spawn you at a location nearby, It has nothing to do with what happens after that. A lot of the time you can run and hide after spawning and, if you're not having fun like the person/people who are spawnkilling you, you can simply change lobbies.
Right, that's why spawn killing isn't griefing.
To me, griefing is very much a grey area, if anything is even considered griefing at all.
In free roam, no, Rockstar has aggressively patched out all the griefing methods. The few towtrucks that dodged 1.06 will probably be swept up in 1.07.
In jobs and missions, yes, it's very easy to grief. Strangely, Rockstar doesn't seem to be doing anything about it yet. You don't even get Bad Sport for obvious griefing, like destroying vehicles necessary for mission completion.
Maybe they'll switch their focus to that after free roam has been successfully locked down, assuming that ever happens.
There is no such thing as griefing. If you are not liking how things are going then just turn the machine off or find another server etc etc
Of course there is. Saying that there's no such thing as griefing makes as much sense as saying that being killed repeatedly in a PvP game is griefing. Two extremes on the same spectrum which are both factually incorrect.
You mentioned turning your console off if you don't like what's going on, but what if I used the previously mentioned griefing method, where I drag a vehicle with a towtruck to freeze your console? Then the thing you don't like is that I'm forcing your console to turn off. It would be hard for you to then turn off the console to try to feel better about it.
And of course, if you join another public session, I can keep joining and shutting your console off, as much as I want to, and there's nothing you can do about it except set yourself to appear offline and hope I don't find my way into your session through any other means.
If you experienced this, I don't think you would still consider griefing to be nonexistent.