Basically whilst I understand your viewpoint, it will not happen.
No company in their right mind would penalise their customers by forcing them to do something they do not want to do.
It is like saying if you buy a Hugo Boss suit, unless your wear their shirt and ties, you cannot wear the suit.
People quit for many reasons, but you will drive customers away by having such a dictatorial stance.
False "averages" are held by the majority of players who have reached saturation - and finishing with a score of 120 will not make a difference.
False "averages" for players who have not reached saturation (via quitting on a bad round) stand out like a sore thumb when you play them, so they only are mocking their ego IMO.
But a question - playing in a tournament, I save to play later....say 10 days later (after it expires), so does this tournament just "hang" or do the programmers (cough cough) need to then write code to move this round out to a normal ranked round so the person can finish (and I can think of many other scenarios)? Basically there is no easy fix.
I quit very few rounds intentionally and yes I have just hit saturation so I will only go down from here.