We don't always have the time
You may not prefer having your machine controlled, but most companies cannot afford to spend the time to "teach" you how to do your own fixes.
Most call center environments strive for low call times, which translates into getting your machine fixed in 5 minutes if we drive as opposed to 15 or more minutes if we teach you. You may not like that, but it is todays reality.
I don't always agree with it either, but its how I am rated against my peers. You can always ask questions as a tech is fixing your machine too.