You can trade picks in MLB now it's just restricted
The MLB allows Compensatory Picks (that a team gains from losing a free agent), but Regular Picks cannot be traded. Why is that? Well, I would point to a quote from an article I read on ESPN:
"Teams could be stupid and trade away all their picks. Yeah, we have to protect ourselves," one club executive said with an embarrassed laugh. "Is it really good to set up a system in baseball that rewards intelligence?"
One of the problems we encounter as fantasy baseball GMs is that we run across individuals who mortgage the future and then leave when it becomes apparent their team no longer has any assets. All of us trade away players whom we don't believe in or trade for players we have high hopes for. Sometimes we see the players we trade away blossom and players we get turn into busts.
The draft is intended to help us gain future assets, but if we trade them all away, we have nothing to fall back on for the future. Of course, we could make bad choices and draft players who don't evolve into MLB players,
but at least we have the opportunity to make those choices every year if we prohibit the trading of draft picks.
I do not believe we should be allowed to trade picks. It will not interfere with the trading process. It helps insure that a given team at least has the opportunity to gain some assets to be competitive in the future. In this particular league, with a total roster of 50 (30 MLB & 20 MiLB), there is no place to "stash players". With a three round FYPD, everyone has a chance to get some decent players without giving up picks.