I have nothing against this story -- kudos to the Japanese fishermen for solving their problem in an innovative manner. What I do take exception to is holding up this story as motivational lesson:
Instead of avoiding challenges, jump into them. Beat the heck out of them. Enjoy the game. If your challenges are too large or too numerous, do not give up. Failing makes you tired. Instead, reorganize. Find more determination, more knowledge, more help. If you have met your goals, set some bigger goals. Once you meet your personal or family needs, move onto goals for your group, the society, even mankind.That's all very well, but there's another -- admittedly pessimistic -- way of looking at it, from the perspective of the poor fish: no matter what you do, nothing matters in the end; you will end up getting eaten anyway, so you might as well surrender to the shark and get it over with ("Oh, these poor humans will end up with not-so-great-tasting fish? Bite me").
Don't create success and lie in it. You have resources, skills and abilities to make a difference." So, put a shark in your tank and see how far you can really go!
Also, just because the fish taste better, it doesn't mean that they had a hoot, trying to save their asses from the %^&# shark.