Yeah no. If the player decided what is griefing, then you could argue that getting shot at while playing a game like Battlefield is getting griefed since I'm sure some people could get aggravated at getting shot at by other players while playing a game about shooting other players. Of course that would be nonsensical.
You don't get to decide what griefing is, the developers do. They lay out what is expected, legitimate gameplay and what is not. And if what they have defined as legit gameplay causes you 'grief', then the issue is you, not the player causing you that so-called grief. If you equate a game's normal gameplay experience to griefing, then maybe you should do your research better next time before buying a game.
Developers most certainly do not get to decide what is and is not griefing. Spawn camping used to be legitimate play in FPSs, however due to the grief it caused players it has now been mostly engineered out. The same will hopefully happen to reduce the volume of mindless killing in this game. I don't see anywhere in the official documentation of this game where it says 'expect to be blown up regularly for no reason by some random loser'.
Your argument is tantamount to saying that real life murder is fine because the universe allows it.