I'm going to go with quality as the my reason of choice.. Some of us have been around the bush for a while you know.. Pretty much every truly exceptional bud I've smoked to this day came from dirt..
And btw, stagnant 6" RW cubes are a horrible way to go IMO.. Your suggestion definately won't outperform quality dirt!
Oh and your logic regarding airflow is flawed, some air will leak that way, but other air will penetrate.. You mentioned electricity, if you have a large resistor in parallel to a small resistor, current will still flow through the large resistor..
@crazy
Silky makes a good point.. The last thing you'd want to do is effectively air-prune those too close to the base, so be careful about things drying out at the surface too much.. If its an effective method, overwatering should be difficult anyways..
I've actually considered this (and ethylene soil gassing) myself, but never got around to it..