Thinking about the reason why I came to the following result. There must be a logical connection which looks like
IF ... a person is killed OR ELSE ... something is retrieved
THEN -> rien ne vas plus = No quest *to beware the char's game balance (difficult)*
ELSE -> give him the quest
For a Ninja it would be too easy to get his traits (2nd Weapon etc) too early.
That will be the main reason, I'm sure.
Fallagar