If documentation were free, then implementing all the suggestions would not be an issue. In the real world, however, time and resources are always constrained, so documentation is a balancing act between utility and achievability. Moreover, for a company whose revenue depends on service contracts, it might not be in the company's best interests to eliminate client confusion with better documentation. I vaguely recall some story about Bill Gates who objected to having (I think) docx structured in a way that would allow a person to modify it by hand because it would loosen Word's grip. In other words, complexity and opacity can align with corporate interests.
There is another problem with spending a lot of resources to produce great documentation, however, and that is that as the software being documented evolves, the original documentation becomes less and less valuable. Although the original documentation might win awards for clarity and usefulness, it might be close to useless in only a few years, and nothing but another herculean effort will suffice to update it. This might be worthwhile where millions of customers are involved, but for a user base of only thousands or tens of thousands, great documentation that is also current can eat up profits.