Because auto history. They used to make straight-8 cars with two gears, because 'stroker' engines are relatively (for the SBCs reading) torque monsters. Performance is bought at the gas pump. It is so much better to let the engine do the driving, then trying to make it happy by working a clutch. Before lockers/traction control, it would be better to have run up a hill in a higher gear and more speed so that it can bog down the motor before your tires loose grip with the gravel. I hate having to split driving between second and third on my 4-speed, because the Toyota 6-cylinder would be so much more comfortable with a J30 in second gear behind it. The market demanded more gears, Toyota complied. - Strictly my opinion.I always wondered why Toyota went to a 3 speed after the 20 series.... then back to a 4 speed later on. How were the manners/functionality of that early 4 speed compared to the 3 speed?