Wtf? That's messed up. She pointed out one (given major) flaw, that the powerful use their power to become more powerful and keep their positions. But aristocratic societies share that flaw. It's even what this form of society is build around. Democracies try to abolish that flaw. That's the point! Well, every form of society has that flaw, even practiced communism.
One could also argue, that rich people tend to wage their wars with money instead of the sword.
And don't get me started about the "One should accept the position one is born into."-bs. It isn't just inhuman to cut away that degree of freedom (Just because people won't die from this, it doesn't mean they don't suffer. It seems that people have in inborn instinct for this kind of freedom, as criticism of "accept your position" always turns up.), it is also very stupid, as you hinder a major part of potential of your people to emerge.
One could argue that societies exists to give people security. True enough. But this is just the means for them to live happier lives. If you accomplish to maintain security by taking away too much happiness from the people (just so much they instinctively notice the absence of something they truly want), that form of society isn't needed anymore, as it failed one of its major purposes (, if not even THE major porpose).
I'm also glad others criticized that part of the chapter, too.