Nobody's reading between the lines, it's just not that unusual for teams to not have player progress through 6 levels of minor leagues in 3 years, especially if they are drafting younger players overall. Sure, there's occasionally a Mark Appel who stays in college ball for an extra year and starts out at a higher level of the minors, or a Mike Trout/Bryce Harper/Jose Fernandez that gets bumped up ridiculously quickly and catches on, but those are by far the exception. Right now, at A+, AA, and AAA, the Cubs have some of the youngest players in each league, so they're not overly conservative, either. Which should tell you that 1) Development is coming along just fine, and 2) Expecting players to go through 6 levels of minor leagues in 3 years is pretty unrealistic, so it's not that amazing that no real Cub prospects have done so in the past 3 years.