Perhaps thieves, who have only short opportunities in which to act, are more efficient time managers than scholars. (See http://forum.wordreference.com/showthread.php?t=1034064 )

The saying, "One good thief is worth 10 good scholars" refers to the act of plagiarism, inspiration and taking other's ideas and adopting them as your own. Specifically, one thief can steal or take the knowledge of 10 scholars and adopt them as their own and thus through this act, the thief can assume just as much knowledge that the 10 scholars had collectively, minus the time and effort it took them to gain that knowledge or do the work needed to gain such knowledge. Source : http://forum.wordreference.com/showthread.php?t=1034064