Dr Fallout
Centurion
Not necessarily, a lot of criticism comes from the fact that the game play isn't necessarily bad, but because it takes away from the role playing and skill aspects which you don't have to play the game to see.I think criticizing lore-breaking is fair enough even if you haven't played it; criticizing gameplay just rings of hypocrisy if you haven't experienced it, though.
If you haven't played the game and you have qualms about its gameplay, it's probably best to preface your statement with it.