This book is about how we as product managers think about product development. We are very opinionated when it comes to building products.
All the guidelines are guidelines… They are not rules set in stone. The purpose of a guideline is to liberate you. They are not meant to constrain you. When you come across a situation, the guidelines will help pick your default decision. This way you only have to use your limited brainpower for situations that deviate from standard. There is marginal gain is designing a new custom data collection method. Its like the 80/20 rule. 80% of the time you should be able to get away with using the stuff mentioned in the guidelines.