A parable about sustainability

On page 170 in Beyond Civiliation Daniel Quinn uses a parable to describe how using a flawed plan with the best pieces will always fail and using a viable plan and ordinary materials will succeed. What I took from this is that it is foolish to keep on tring to rebuild something to make it better when it doesnt work! Instead we should think of something compelty new that does work. That can apply to almost everything involved in our society... Like he said earlier in the book, we put so much money into schools trying to make them "better" and into trying to improve the laws to make them "better"... Why do we do that year after year? Do we feel obilagted to because we are provided the money? Or are we just to lazy to think of a new method?