I personally believe the reason QBs tend to be in the middle of the "1st Round" debate is more influenced by the importance of the position.
A QB handles the ball on every play. No other offensive SKILL player has that much impact upon the game. Moreso, as a result of a QB's interaction with the ball, he enables all other offensive skill players. Thus, his skills are more than self-serving.
As a result of this responsibility and impact, organizations commit more resources to the QB position than any other. While some may lobby all 1st round draftees receive a large amount of resources, the QB is an enabler and image of the team's offense. WR's, TE's and RB's can possess large images in the fanbase, but the QB enables that image.
With so much importance placed on a 1st round pick and the QB position, it also becomes a good measuring stick of a team's ability (as an organization) to pick, manage and produce a winning product. As, even in today's market, the QB is still the face of the organization.