Why transformer kva and moter kw?

first we have to know the difference between va , var and w

- va is the apparent power

- var is the reactive power

- w is the true power

so Why transformer kva and motor kw?

because transformers will change the voltage but you will get the same apparent power

ware the motor torque need true power 

if they used kva you will not know how much torque dose it have