Because they want to have DC motors, while Tesla uses an AC motor. There are various advantages disadvantages to both. DC motors require permanent magnets. The AC motor on the other hand has the problem that the power coming out of the battery is DC. So it has to be converted back to AC in order to be used in an AC motor.
The Tesla has a large inverter that converts the DC to AC. Most other makers choose to have a DC motor in order to remove the need for an inverter.
Some people joke that Tesla chose an AC motor, because that was the motor invented by Nicola Tesla. But the AC motor has other advantages such as its excellent torque curve. The latter ensures that the model s has no gearbox while it features amazing acceleration at all speeds.
Well, I know for a fact that the Leaf also uses an AC motor with an inverter. It's documented all over the place. But, they have permanent magnets in theirs, while Tesla apparently does not.
The Tesla has a large inverter that converts the DC to AC. Most other makers choose to have a DC motor in order to remove the need for an inverter.
Some people joke that Tesla chose an AC motor, because that was the motor invented by Nicola Tesla. But the AC motor has other advantages such as its excellent torque curve. The latter ensures that the model s has no gearbox while it features amazing acceleration at all speeds.