I'm reasonably sure that the request being discussed is referring to DF runs and the like where you don't really have control over your party members. People who are receptive to improvement aren't who the topic was created for and the people who need the improvement and refuse to change aren't likely going to be lured in by even stricter optional runs even if you dangle some tasty carrots in front of them. They're just trying to pass, not make deans list.
Having optional objective rewards sounds fun and like something to add "content" using existing resources, but wouldn't affect the problem population this topic is about.