I never said this is fair... and I dont even understand why they nerfed consoles like +Hazzard Systems which are pretty weak anyway.
But for some reason they did and they dicided to grandfather the Old Consoles... maybe as a little thank you to the players which where supporting this game through the tough start.
Right now those Consoles may seem overpowered, but I think people are overreacting. Keep in mind they are only green... I'am pretty sure sooner or later they will add Purple Consoles to the game, just like Purple Phaser, Disruptor, Quantum, Tetryon Weapons and whatever is missing right now... and once this happens nobody will care about some old players having green consoles equal to their new purples.
That's not gonna happen for a while, seeing as a green legacy console is the equivalent of a Mk XX (Mk 20) new-green, a Mk XVIII (18) new-blue, or a Mk XVI (16) new-purple. So... a level 100 green, 90 blue, or 80 purple.