Vehicle Mounted Turrets- Is there a point?

None of the vehicle turrets I’ve seen (with the exception of the the Laser Rifle and the Tesla Cannon) have ever seemed worth using to me. When you fire them, they fire all over the damn place instead of where you aim them, which defeats the point of aiming in the first place (and I don’t think I’ve seen one that fires Burst or Semi-Auto). Its easier for me to just get out of my Deathmobile and rip apart the zombies on my own; they pose little threat to me, and I can train my skills this way. In fact, my current character is almost at a point where they’d be better of firing an M60 on their own instead of mounting it on a vehicle.

Am I doing something wrong? Or are Vehicle Mounted Turrets just bad?