Hands on teaching is a shortcut to deal with the time crunch
With few exceptions I will not touch my clients, meaning I won't do things like skiing backwards in a wedge to keep them from flying down the hill. I want them ready to do it al on thier own. I want hem to ski offensively from day one and if I rush them, that may not happen.
The secrets to hands on teaching are using contact at the points where movements need to be made (e.g. grabbing the boots in the middle to steer into wedges instead of holding the ski tips), using the least amount of contact possible (e.g. helping versus forcing) and reducing the force of contact as performance improves (e.g. transitioning from holding the boots to holding the tips or providing less and less help in either frequency or intensity).
There are lots of examples of "hands on" teaching (or training aids) in other sports. I've experienced this on the recieving side in my golf lessons from different pros and seen it from the top teaching pros on TV. I've also seen and personally experienced hands on teaching failures. Like all tools, it has its pros and cons.