I have yet to see a study that shows the Pirates can’t draft.
Let me clarify that. I’ve seen studies showing the WAR results from players the Pirates drafted, comparing those to the results from other teams. But developing baseball players is a complex process, with many steps between drafting a guy and seeing him show up in the majors — not to mention steps that are needed after a player has arrived.
Baseball is unique in that way. You draft players in football and basketball, and they step into the pros right away. The NHL has a minor league system, but not nearly as deep as the one in baseball, and the best players tend to be up right away or within a year.