It doesn’t quite have the satisfaction of a good back and forth grudge match (on account of being a PvE game),

Heh… It’s not designed for it, but I’ve had some pretty grudge-like experiences joining public games, as some teammates turned out to be hostile.

To be clear, I don’t recommend that experience. It’s not fun to be antagonized with deliberate friendly fire throughout a mission, bullied by a group when you eventually shoot back, and left for dead when the ship leaves. (It’s easily avoidable by playing with friends, of course.)