In the back and forth koans, why are the masters such assholes?

Because Zen is a discipline and not a relaxation technique.

File: homer angry.jpg (96KB, 909x878px) Image search: [Google]

96KB, 909x878px

>>9621929
because one day you'll thank me for all that scary love.

>>9621931
This

>>9621929
Some of them might just be assholes, others are assholes to break your ego, or at least crack it. This reminded me this episode of Hakuin's life:

>Hakuin left again, to study for a mere eight months with Shōju Rōjin. Shōju was an intensely demanding teacher, who hurled insults and blows at Hakuin, in an attempt to free him from his limited understanding and self-centeredness. When asked why he had become a monk, Hakuin said that it was out of terror to fall into hell, to which Shōju replied "You're a self-centered rascal, aren't you!"