I have to think the shrinking of the minors and their efforts to stall a player from gaining free agency as long as possible are two parts of the same piece. As college baseball has improved, with more top players going to college (just a third of first round picks were HS players), MLB teams are a) relying on their play in college to deliver a better prospect for potential MLB success with more data and less risk involved in drafting them, and b) they aren't paying for those years of development and c) they'll still stick a guy from college in the minors for two years meaning by the time they DO hit their FA year, they'll be 29 or so and the team probably enjoyed the bulk of their productivity under the team control.