@dsc810 quite off topic now, but yes, in times gone past the same signal was used over here, but it was discontinued as it was deemed extremely unsafe and isn't allowed anymore (although some of the older crowd might still use it, if somethings happens insurance won't pay a thing then). Radio communications are required between winch and launch point as well as between launch point and glider, however every club i flew with had an additional radio on the winch to monitor the glider fields frequency for exactly that kind of command as it is of course faster than communication via the launch point. Current requirement for overspeed is to disconnect and depending on height land back or straight ahead.
And of course certification requirements between gliders and airlines are vastly different, so on the rudder issue, which is used much more often in gliders, it is probably something about apples and oranges.