The modes are "fair" - all game features respond to PvE actions in any game mode.Freedom of choice is great, but it should be fair, with all modes equal. Currently while open is more fun (for me anyway), solo and PG give unfair risk/reward balance - i.e. unequal. In some content I think nobody minds that, but in PP, there are reasonable objections.
That some players enjoy the frisson of PvP is a choice they make, which means that any setbacks they suffer as a result of PvP when engaging in any game feature are down to their choice to engage in an optional aspect of the game.