All that the math suggests is that the escape velocity from inside the event horizon is beyond the speed of light, so it's physically impossible.
It doesn't seem impractical to be able to establish an orbit inside that radius, though, even a highly elliptical one, provided this orbit never slings you back out. It just seems if your orbit decays even slightly, you'll never be able to recover, leading to the inevitable conclusion of being pulled directly into the singularity.
Since the event horizon itself is supposed to be a fairly non-event to cross, why can't you just fly in a lazy circle around a large black-hole at a relatively "safe" distance and maintain an orbit that's decaying only very slowly?
It doesn't seem impractical to be able to establish an orbit inside that radius, though, even a highly elliptical one, provided this orbit never slings you back out. It just seems if your orbit decays even slightly, you'll never be able to recover, leading to the inevitable conclusion of being pulled directly into the singularity.