Those folks believe a 20-10, 4.50 ERA pitcher who throws for a team that scores 5 runs per game deserves an A while a 15-10, 2.50 pitcher who throws for a team that scores 2 runs per game doesn’t.
This is particularly true for those who think that pitchers can “pitch to the score” (despite evidence to the contrary) and therefore the pitcher win statistic is somehow meaningful. As an addendum to an earlier post, I understand that some folks wouldn’t be terribly keen on changing pitcher grades.