MLB players and their representatives will always view the demand for higher MiLB salaries as a zero-sum game; with a dollar given to minor league players as a dollar taken from MLB players' pockets. Plus, they view the minor league experience as a ticket to be punched in order to qualify for the potential for MLB riches and fame.
Meanwhile, I will always carry the opinion that major league front offices would prefer that minor league players "self-select" themselves from minor league rosters; rather than releasing them, outright. The more onerous the compensation and overall conditions, the more likely that players at the margin will decide to move on to other pursuits.