Generally speaking, the conditions on the summit push are so close to the edge of survival that it is not generally possible to launch rescue operations.
Also, people who have spent all that time and money to get to the summit ridge aren't anxious to abandon all that to help somebody in trouble. :)
Plus helicopters can not fly above, I believe, Camp II which is about 24m’. Even there it is apparently not enough air to get much of any lift on the rotors. They tend to take off and almost fall down hill.