The fact that MLB spent money on lobbyist to get Congress to specifically protect baseball from wage laws makes it clear that that MLB owners were concerned they were doing something wrong and needed to try to get ahead of the issue.
Very few MiLB players are playing for the money. They have spent most of their lives developing skills to simply have the opportunity to compete at the highest levels possible with the dream of making the Show. A basic living wage would not be enough to motivate a person to dedicate the time and effort to succeed at what is essentially an elite level of a profession. I do believe they have earned the opportunity to be paid a wage adequate to live on. $5,500 a season for an entry level player is truly absurd. Considering they pay for insurance, club house dues, etc... they don't have to worry about taxes. MLB owners are simply pinching pennies where they can legally do so and where the employees have no legitimate way to fight the issue. MiLB players have little leverage even if they had their own union. The other real culprit is the MLB Players association that is taking from the poor to pay the rich. Simply reducing the MLB payrolls by 2-4% would be enough to pay all MiLB players a minimum of $30K. This is not a significant wage to get excited about.
Congress clearly should focus on other issues.