The interaction (fighting the other player in Battlefield, tackling the falling pieces in Tetris) is desired. What is unwanted in your examples is the result.
From my point of view, not killing, but making it bearable and enjoyable. Apart from pure PvP games without PvE elements, it's been a few years since I last purchased any game where I couldn't completely remove even the slightest possibility of PvP, and I doubt I will ever spend another cent in any game where I can be forced into a PvP situation against my will.
Right now it's the opposite. There are but a handful of MMOs where the player has no choice but accept that non-consensual PvP can happen. Most MMOs, though, either have no PvP at all in the main world (The Secret World, Guild Wars 2, Elder Scrolls Online, Trove, Star Trek Online, Marvel Heroes, etc) or have the option of PvE servers where PvP is restricted to specific battlegrounds and arenas (WoW, Star Wars: The Old Republic, Age of Conan, Wildstar, DC Universe Online, Rift, most WoW clones, etc).
It's funny how you' listed GW2 as the PVE example. I didn't play all of the listed games, but some. "The restricted PVP arenas (more like continents)" is where the majority of the game traffic is. Almost the same happens in ED just PVP zone boundaries are not strictly defined. 5 minutes of space travel and you're have very little possibility of PVP interaction.
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