sorry, that's bs; do your homework.
nitrogen does not cause the harshness of unflushed plants at harvest. chlorophyl does. extra nitrogen means extra chlorophyl; that's where that old wives tale comes into play.
now, if you feed well, your plant will never go through necrosis, you overall yeild will be much higher, as the fan leaves are the solar panels supplying the energy for making and metabolizing nutrients. and (here's the kicker) if you flush a week before harvest (LIKE YOU'RE SUPPOSED TOO) you will have no nutrients to sweat out, and a lower overall percentage of chlorophyl.