The sherpas are paid per kilo of litter that they bring back. Visiting climbers are also encouraged to participate.
There is a permit system in operation already, but it's very 'light touch' and doesn't ask for much in the way of climbing experience. Consequently you can have cash rich and experience poor groups of climbers who have pad through the nose to go up, but who don't have much track record of altitude climbing. There are stories of climbers not knowing how to use ice axes properly, or attach crampons.
Everest is not the most technically challenging climb, but the altitude is - literally - the killer. As soon as you enter the death zone you are on a countdown - which is why delays in attempting the summit are so dangerous because you still need to get down again. The 1996 tragedy was significantly worsened by climbers attempting to summit later in the day than they should. There are also bottlenecks at key crossing places such as the Hillary Step and that will only be exacerbated by inexperienced climbers.
The woman who called for help and who was left to die was Francys Arsentiev. She'd summited, late on, without using oxygen and then become separated from her husband (her climbing partner) on the way down. Due to exhaustion they had to stop and spent overnight in the death zone. A climbing team found her and managed to get her part way down by giving her some of their oxygen, but they also ran out and were too exhausted to move her any further. and were forced to leave her. Another team found her the next day when they were on their way to the summit, still alive. They also tried to help her but she was so far gone and could not move and there was no way that they could have carried her. It's worth noting that this team actually called off their summit attempt because they stayed to help her and when it became apparent that they could do nothing for her, they went back to the camp.
Climbing at altitude is exhausting. Rescuing people when you are in the death zone and you are literally dying on your feet every hour that you are there, is not as easy as dragging them with you. It goes with the territory that if you put yourself in harm's way, then you accept that whilst people will help if they can, they will not - and should not - endanger their own lives to do so. Just one more reason why inexperienced climbers should not be allowed up.