Here’s the problem: the judges are human, and they’re humans who have enjoyed enough good fortune to become judges. The quality of their mercy is strained through their life experiences, which don’t resemble the life experiences of most of the defendants before them.
Judge Aaron Persky empathized with Brock Allen Turner and could easily imagine what it would be like to lose sports fame (as Persky enjoyed), to lose a Sanford education (as Persky enjoyed), to lose the sort of easy success and high regard that a young, reasonably affluent Stanford graduate (like Persky was) can expect as a matter of right. Judge Persky could easily imagine how dramatically different a state prison is from Stanford frat parties, and how calamitous was Turner’s fall. That’s how Judge Persky convinced himself to hand such a ludicrously light sentence for such a grotesque violation of another human being.