Why not?
Because I see a difference between being able to "make it back", and "maneuver effectively in combat" with a missing vertical stabilizer.
If the "stub" is enough to create a weather-vane effect, I could see the possibility with careful use of throttle and a gentle hand on the stick to limp back home, and possibly even get it on the runway.
Active maneuvering, like moot describes? Nope, I don't see it...
The vertical stab isn't optional, and it isn't designed to be big enough to do its job as long as a small portion of it is still there. It's designed to do its job with a minimum of materials, weight. Once part of it is gone, it's below that "minimum" and shouldn't be able to still perform like it was there. It isn't like the designer says "well, he's gonna need this much, but we'd better triple the size of it so if he has 2/3 of it shot away he can still finish the fight".
In active maneuvering, at relatively high AoA and slow speeds, I'd expect adverse yaw effect to be more than enough to wreck your day. Throw some torque in, and well, no, I don't see it...
The damage in that film was neat, and in some of those instances I could see "possibly getting home, but not fighting. It's not like they didn't ignore some effects either. That F4U on fire for example, has fabric elevators and rudder, but they withstand the flames just fine... Obviously, AH still doesn't model the full burning effects either. But at the end of the day it's just another "artists interpretation", and I personally don't see the end result being any better than what we have in AH. Graphically, maybe more impressive. But then, that may be what I'm seeing too. A "more impressive looking" amount of damage, who's effects aren't modeled in the FM as intensly as they're modeled in the graphics.