3.5/4
I don't know why people hated it, it wasn't really a revolutionary work on finance by any means but it did bring to light many principles of trade and prohibitions regarding it for those who have not been exposed to it.
If you want to learn deeper about traditional Islamic finance then this is not the book/method for it. This gives an overview of the Islamic approach to money, trade, and work and how we should aim to prefer and give precedence to Islamic teachings with these things.
It does go more into Islamic principles and move from the topic of money to exploring what Islam is and what the 5 pillars include for example, not a bad thing, just wouldn't say it was necessary to go into the detail it did for this sort of book. Though, others probably needed to read that far more than I did and it's not harmful.
Oh, and I saw some criticisms of impractical advice within it, which is subject to each reader, but generally it is not bad advice. It is *better* to avoid doubtful matters, of that there is no doubt. However, when dealing with a wide scope of Muslims you will find many struggle with leaving the clear evils or doing the clear obligations, so I can understand why many people react to such advice as if it is totally unfounded or ridiculous - but they're wrong there to put it plainly.