One should never forget that baseball is exempt from anti-trust legislation for 100 years now.
This is a shield that combined with the CBA with the Union allows for a massive constriction of pay for labor as it enters the industry.
I have always believed that the professional drafts are highly suspect legally. There is no other industry that I can think of that mandates where you will work and how much you may be paid as much as professional sports.
Most choices come down to if you want the job then we need you to move here. If you don't want to be a lawyer in NY you can be one in Dallas if you prefer. Not so in professional sports if you are drafted. If you want to play and we draft you then for 4 to 6 years you go where we say. WTF?
As long a the unions are willing to offer up rookies to drafts and signing restrictions this is unlikely to change.
This is laid bare in baseball because in an incredible irony non US players are not subject to the draft. This created a glimpse into how much money might be available in reality.