The Orlando Sentinel's Brendon Sonnone took a stab at explaining these numbers this morning, pointing to the amount of time Florida State's backup offensive line played and Jameis Winston's penchant for holding onto the ball in the pocket.
Sonnone is at least partially correct, as FSU's backup quarterbacks were sacked one every 11.3 dropbacks in 2013 as opposed to Winston's once per 15.2. But the problem with the latter suggestion—Winston's tendency to hold onto the ball—is that FSU's sack rate has never been especially highly ranked, even before Winston was the starter.
The primary reason for FSU's lower-than-might-be-expected sack rate is quite simple and can be explained by noting which other offenses have high sack rates:
Worst #ACC pass pro in 2013: Pitt (1 sack/10.3 drop-backs), NCSt & BC (1 per 13.2), VT (1 per 14.1), FSU (1 per 14.4).— David Hale (@DavidHaleESPN) June 30, 2014
One thing Pitt, Boston College, Virginia Tech, and FSU all have in common on offense: each of their offenses throws the football downfield more than the average, meaning more deep drops than the typical spread offense focused on throwing short, quick passes.
It's a strategic trade-off, with big downfield passing opportunities offsetting a slightly higher sack rate. This decision was obviously worth it for FSU in 2013, as the Seminoles were second in the nation at 10.0 yards per attempt, sharing that spot with LSU—whose sack rate of 7.69% (approximately one sack per 13 dropbacks) unsurprisingly trailed FSU's 6.83%.
There's no doubt that Jimbo Fisher would prefer Winston get rid of the football a bit earlier at times, and offensive line coach Rick Trickett would certainly like his unit's sack numbers to improve. But the reality is that Florida State's aggressive, downfield passing attack is going to result in higher sack rates than the average college offense at this point, and that's okay—so long as the big plays ultimately outweigh the extra half sack per game.