From John Sickels' interview with Dayton Moore:
When I got here, the farm system was almost empty, so we were starting from scratch. But even if you have a perfect draft, even if you are 100% right about a player, it can still take him three or four years to get to the majors, then another two to four years before he becomes a consistent performer.
When Terry Ryan took over the Twins in 1994, it took them six or seven years to get to the point where they were consistently competitive. It doesn't happen overnight. But that is the model we have to follow to be competitive in Kansas City.
How empty was the farm system when Moore arrived?
Dayton Moore was hired by the Royals in June 2006, too late to play a role in the amateur draft.
At that time, the farm system wasn't entirely empty. Alex Gordon, who'd been the No. 2 pick in the 2005 draft, was tearing up the Double-A Texas League and would be widely considered, the following winter, the No. 1 prospect in baseball. One of Gordon's Wichita teammates was 20-year-old Billy Butler, also considered a brilliant young hitter. And the Royals had Luke Hochevar, who had just a few innings of professional experience after being drafted seventh overall by that summer.
Otherwise, the Royals didn't seem to have much. John Sickels' list of the top 50 hitting prospects, published prior to the 2007 season, included Gordon at No. 1 and Butler at No. 7, but nobody else. His list of the top 50 pitching prospects included Hochevar at No. 10, and nobody else. The Royals didn't have many Grade B prospects.
You never know, though. At the same time, the Giants' farm system looked even worse than the Royals', with just one premier prospect (Tim Lincecum). Sickels rated Jonathan Sanchez a Grade B prospect, Brian Wilson a C+. (Speaking of whom, Sickels also gave Kansas City's Joakim Soria and Brian Bannister C+ grades.)
The problem with the prospects Dayton Moore inherited isn't that there weren't enough of them; it's that not enough of them actually developed. Butler's a good major-league hitter, while Gordon and Hochevar are still trying to establish themselves. And none of their Grade B prospects developed at all.
I think Moore might be overstating, just a bit, the sorry state of the Royals' farm system when he took over. It wasn't loaded, but neither was it barren. Not at all. The following winter, Moore wrote the foreword for the Baseball America Prospect Handbook ... according to which, the Royals' farm system was the 11th best in baseball.
I think it's probably true that once you got past the Royals' excellent prospects, the cupboard was largely empty, which did lead to a drought of high-caliber talent in the upper levels of the system for a few years. And thanks to Moore and the people around him, all of that has changed.