Develop and maintain a useful, valuable and resilient product. Improve return on investment of product development resources.
Check out the user perception perspectives of the product health check.
Check out the product owner perception perspectives of the product health check.
When somone describes a product as being difficult to use, it means that they are having a hard time completing key tasks, or perhaps even understanding what those key tasks are.
Whenever people are unable to complete a task, or the completion of the task involves what they consider to be unneccessary friction, their feelings of frustration (and possibly anger) grows.
This feeling inhibits their ability to think clearly, which in turn makes it even more difficult to complete the task or better understand how the product works.
Likely results of a product being considered difficult to use is that:
Product management
Executive roles