Did you read the post? Deaconblue says he used the handbrake in FWD cars to swing the rear around curbs. He used it to break traction, not maintain it.
Your understanding of how a FWD transmission doesn't matter. An open diff is an open diff. It's irrelevant how any of them operate internally because the brakes are only directly affecting the wheels. All that matters is how much the diffs will let the wheels rotate relative to each other (open=100% slip, LSD=~25%). You don't have to be arrogant about your complete disinterest in FWD "trash" and how poor their drivers are. Have you considered the increase in number of vehicles on the road, increase in population, and increased prevalence of FWD/AWD/4WD vehicles in your observations about most vehicles in the ditch being one of those drivetrain configurations? From 1970, the number of passenger vehicles has gone from 111,000,000 to 233,000,000. The US population has gone from 205,000,000 residents to 316,000,000. Both have approximately doubled. I can't find stats on RWD vs FWD sales, but the trend is apparent in that time frame.
Using the handbrake is applying a negative force on both drive wheels, effectively reducing total torque of the engine, not necessarily the individual wheels. Applying a left or right rear handbrake independently will absolutely regain traction, but I cannot see how applying the handbrake to both can increase traction any better than a higher gear with lower wheel torque.
