I would agree that the way homeopathy is done most of it is worthless, but there are a number of non-medicinal remedies that do work (anyone care to claim that use of Vitamin C and Zinc are ineffective on colds?)
But this book is basically just another of organized medicine's slams on anything that threatens its cartel-like powers to control the delivery of sick care (we do not provide health care in this country, most doctors are too busy treating symptoms of problems, not preventing illness). A large part of what is claimed by the book is probably either misleading or is simply 'tarring with the same brush' ineffective practices with things that might have value.
One example, the claims by manufacturers of FDA unapproved products that 'this product is not intended to cure, prevent or treat any disease'. They are required to say this because if they make any claims at all not proven by double-blind studies their products are subject to seizure and fines. If a seller of limes (the fruit) was to announce their product cures scurvy - absolutely known to be true since the British Navy started giving limes to sailors, hence their nickname - the company would be in violation of FDA rules and its crops would be seized and destroyed, because federal law makes it illegal other than for a manufactured drug which is licensed for distribution by the FDA to claim it can cure any disease, even though the statement is true.
Some of these practices - especially chiropractic - may have use in some cases. But this is an old, old rivalry; MDs hate chiropractic and have been trying to have it outlawed for decades. There are many people who have had relief for various conditions as a result. But since it can't be patented, nobody is going to spend huge amounts of money to do double-blind tests on these various methods, because organized medicine - as well as pharmaceutical companies, who, if people use other methods, they get less money - sees it as cutting into their profits, and it's best that there be no evidence available to argue in their favor.