Bribe
The more shellfish you have, the more you can bribe people. That worked in the olden days when shells were money, and today too if the people you want to bribe really like seafood.
Imagine bribing a bunch of yakuza and politicians with all the shellfish you have. Ohohoh, you'll never be caught!
わい
まかな
None
Welp, the cops found out about your bribe, that didn't last long, and now your entire family is watching you get put into the police car screaming, "WHY (わい)?!
Yeah really, why? Why bribe people at all. You could have just been rolling in shellfish dough. Why risk everything? And you counter with. Why not?