You only obtain one in Gen 1, and has since been a rare pokemon since. It'd be a "delicacy" to catch one.
Its japanese name is the combination of duck and onion, while also referencing an idiom of running into a wild duck with an onion- a far fetched occurrence, but a pleasant one, since it'd make a tasty meal. The idiom can also be interpreted as the duck getting itself in a bad situation by holding an onion, which parallels the player getting themselves into a bad situation by using this pokemon/trading away a potential Fearow.
tl;dr: it's shit for a reason
/autism
