Don't let the bullies grind you down.
It's interesting that it kind of tries to psychoanalyze the cause of bullying: they feel inferior, they need attention, they're frightened, or they're angry. Basically it suggests that you start off by being nice to them. If that doesn't work, stay away from them. Which I guess is good advice, but also pretty common sense. If that doesn't work, ignore them. If that doesn't work, confront them. But never fight them, only run away. If that doesn't work, tell an adult. Which will magically fix the problem.
It's not bad advice. It's certainly not saying to appease the bully, which could get people in a lot of trouble. It's just that sometimes kids might need more help than just this book. It makes it sound like solving the problem is easy, because at the end the problem is solved. It's not really that straightforward.
It's not bad, it's just not very helpful. It's not inaccurate, though, so that's good.