Probably a bent shifting fork or nicked up shifter drum.
There is no real advantage to removing gears, if they are not engaged and pulling there is very little power lost to friction. The friction happens when you put them under a load. I would classify this as an old wives rule (stupid). Removing the two gears would net maybe a pound and a quarter and no Horsepower gain. Just My Own Humble Opinion.
Honest Dad himself
