I concur on flushing is unnecessary and also that light leaks do seem to induce hermies especially in fem seeds if often and bright enough. Jury's still out on how much light etc.
Furthermore I believe the flushing myth was spun out of 2 things actually.
One is the practice of "drowning the roots" in h20 for 10 or more days as this begins the fermenting or curing process while the plant is still alive. As we produce lactic acid to continue on without oxygen or nourishment so does the plant begin fermenting the sugars and carbs into alcohol to be able to sustain itself and survive. Also the days spent attempting to "wick" off or transpire the water out of the root zone the plants metabolism is sped up into overdrive which pushes whatever productions are occurring to the maximum. This practiced has morphed into the harvest flush.
The other is that the "dutch" breeders have pushed and pushed the nutes to their strains especially Phosphorous in the flowering stage and this does effect the plant as it is denied other elements it really needs to function properly so these breeders resorted to flushing pre-harvest in an albeit guilt ridden attempt to make up for abusing the plant.
Hope this sheds some light...
Namaste'