User blog comment:The ASL Pirates/The Straw Hat's Devil Fruit Hunt/@comment-24.235.56.170-20150531165408

You're coming at it backwards. It's not that a lot of successful people find Devil Fruits, it's that random people who find DF's will often become successful.

The most DF's that were found at once were Kalifa's and Kaku's, and that was likely because the Marines killed the previous users and knew to look for the fruits. Otherwise, it's just random people stumbling upon the fruits whenever a power holder dies a few towns, or even islands away.

People aren't good at seeing the pattern, the Marines know about it, and DF users rarely die immediately after consuming a DF, so it's likely to stay in one person for decades at a time.

This all comes together to make it very hard for a specific pirate crew to find a new fruit. Whereas, in the other direction, a fruit may have several different owners during the exact same timespan.