the trait being there doesn't mean it's useful if it's so damn slow it has next to zero impact (which is true when you compare to a JP that has faster rotation). If your argument was sound the FF wouldn't be a sitting duck the moment something gets close like all casemate Tank destroyers (again JP, stug etc) so it has the same weakness and is not worth calling a perk.
As for your argument it can fire on retreat that's laughable, any player worth their salt will reverse awayway where any TD can return fire with a bit of micro. It's not hard and this is how you deal with diving tanks, not doing a massive U-turn while the snailpace FF turret takes a millenia to turn to the back of the tank or your Stug whatever has their gun pointing away from the enemy.
You conveniently ignore my FF MG point, this I was hoping was where you would understand your leaky logic. What "perks" as you call them are worthless if there are no solid stats to make them useful, this is why I brought up the MG's. They are useless and the FF turret in the grand scheme of things is worthless too.
If you're still not convinced I implore you to look at that firesparks video earlier in the thread, you'll see the JP snapshotting targets and rotating to targets quicker than the 440mp 155fuel firefly.
Except the turret IS an advantage. If you are backing between some buildings or something and the tank is coming up 45° to your right you can do something about it. Hell YOU don't have to do anything the unit will do it itself.
I didn't mention the MG thing because it's stupid. The panzerwerfer has an MG too but if yuu are in a situation where it's even bothering to shoot you fucked up. The turret works at max range. And being able to back up full speed and shoot is better than spin shooting to get shots off. The kv-2has a slow turret too but there's no use pretending its just an isu.
It's way better to have a turret, even a slow one than not have one at all.