As a tow pilot, I have no problem letting the glider steer me.

As a glider pilot, I have no problem giving the tow pilot directional suggestions. However, If the tow pilot is unresponsive to my suggestions, I don't push the envelope much past the normal wake boxing position.
That would be stupid.

Once a glider pilot tried to steer me toward a bank of clouds at our current altitude, and I refused. He was frustrated I guess, because he yanked my tail in the same direction a second time, as if forgetting to release the rope. The tow was an instructional flight and the instructor was attempting to demonstrate steering. He could have easily gone the other way, which was clear of clouds. So, I terminated the tow.
See ya...

The practice isn't inherently dangerous, done correctly. Some pilots don't.
Jim.