Here’s an article from mlbtraderumors.com which states that the MLB Players’ Association is not opposed to the idea of allowing teams to trade draft picks. Neither am I.
The article suggests that teams are concerned that allowing the trading of draft picks might give amateur players leverage because they could demand trades to the teams they want to sign with. That’s certainly a possibility, but I think it’s far outweighed by the advantage to teams of having another option on how they go about building themselves up for the future.
Draft picks as a group have a definite value, and the people at fangraphs.com and elsewhere have put a value on what players in each draft slot are worth on average. Their estimates may be more or less accurate, but they are based on facts (i.e., who got drafted in each draft slot in the past and the total value of those players as major leaguers divided by all players in the group), so these values are certainly reasonable estimates of value.
However, baseball draft picks are certainly less likely to develop into major leaguers than NBA or NFL draft picks—but that’s still not a valid reason to prevent MLB teams from trading their picks. Some teams value draft picks more highly than others, and teams can already lose late first round or early second round draft picks by signing Type-A free agents.
Teams like the Pirates or the Royals might well benefit by being able to trade their high first round picks for players who are already established Major League players or prospects playing in the high minors. The poorer, second-tier teams already make decisions not to draft the best players available at their draft slot, because they have concerns about their ability to sign those perceived as the top draft picks.
Allowing teams to trade their draft picks if they so choose gives every team more options in trying to build up their clubs in the future. I don’t see how that can be a bad thing.