Unfortunately many people who take the import route are new to the game and dont know where to start and would hands down prefer to let an experienced broker assist them with the process. I know several japanese agents and after importing my first car and learning what is required I would have no problem bypassing a broker on the next occasion.
Most people dont have the luxury of direct contacts in Japan so its pretty damn simple to understand why the majority of buyers importing their own car choose to use a broker.
I think everyone understands that you dont approve of brokers or the fees they charge but there really isnt a need to ram your opinion down peoples throats at every given opportunity.