There are other (better) but more expensive ways to prevent damage to the motor. The plastic gear in a mixer is the cheapest way to solve the problem while also

There are other (better) but more expensive ways to prevent damage to the motor. The plastic gear in a mixer is the cheapest way to solve the problem while also ensuring the device wears out fairly quick compared to a better built unit. It’s a win win for the manufacture while a total loss for the consumer (and environment)