Trying to understand Electric Power Steering

[Vaiti]

I am trying to understand how electric assisted power steering works.
The basic principle is that the wheel has to turn more than what is
applied on the steering wheel using a electric motor(basically to give
the driver a better feeling about the vehicle). As far as i have read,
torque is controlled to do this.
My doubt is why not speed ? Why not control speed to achieve this ? Why
can't motor running at more speed create more force ?
The question may be basic but will help my understanding of the system.

Thanks.