As stated in countless other reviews, the premise and message in this book is rather simple: If you want to have money for retirement, save as much as you can and invest those savings in indexes that track the overall performance of market. The reverse is to gamble, and try to beat the market - something reserved for having fun and money you are willing to lose. This is sound advice and arguing against it seems unwise (mostly because there are countless other books and investors offering the same advice - checkout the million dollars challenge with Warren Buffett). If you’re still not convinced, just pull up a graph that shows something like the S&P500 since its inception. Spread out over time, that graph clearly shows why investing in the stock market with sound, tested principles is a viable path to retirement wealth.
There is more to it as well though. You should have periodic review of your investments... even if they are in indexes. You should map out your investments over time, so you know when you should diversify and can minimize heavy losses closer to retirement. You should also verify fees associated with your investments. For example, mutual funds, even when the fees feel low (say 1%) accumulate over time, and when mixed with the cost of churn (constantly buying and selling stock) can become incredibly expensive over the long term (hundreds of thousands of dollars expensive).
It’s information like what I mention above that warrants the five star review. I consider myself and intelligent guy, and I’ve certainly been lured by the appeal of making money in the stock market... but always turned away, not wanting to risk my savings. I had zero understanding of how all this worked, and consider myself much more informed. In a way it took a lot of the magic out of investing, and that’s exactly what I needed.
What this book is not, is a guide to wealth across all facets. It does not aim to make you a millionaire in ten years with just $100. If you are closer to retirement than others, you must expect to build less wealth. If you can’t save any money, but have time you may be in a similar boat. I’d say the target audience are readers that are putting money in their 401k (maybe not as much as the should), and had no real idea which funds to pick. If you keep that in mind, and that matches you, this book is probably all you will ever need. As a bonus, you will also get some sage life advice along the way.