It's just how the models are compiled. I can't pretend that it's terribly difficult to prepare one illustrative image. Honestly, smithy was the one that looked into this issue and determined the prime road block, not me. But I can still make a pretty picture, lol.
If you slowed down the turret rotation speed (with a detached aim system, like he said), doesn't that help solve the aiming problem—at least, on the heavier chassis? If you can't whip the turret around all crazy-like, won't the passenger not be whipped around as much as well? I think this idea solves two problems, giving lights a purpose and making the 2nd seat usable. I really like this idea now.
it would make it easier, the problem would still be the same, as soon as the turret turns you are put off your aim - now by less, but still ... ... also i just realized, if you just align the players aim to where he was aiming, like i described, youd also negate the tanks total movement keeping the aim perfectly on spot - it would make it "over-stable". so scrap that approach. maybe in the end what spartacus tries might be good enough (its also what would be easily reproduceable IRL, even fully mechanic)
It doesn't completely solve it, but it helps. Considering it also solves other problems, I think that it would be a better use of our Wax Maestro's time.
It's not possible on most of the current chassis in the game. The limitations were discussed earlier in the thread.