As an expert on user and operational simplicity, I have worked with industries, including the medical and pharmaceutical fields, where workers need to interact with electronic user interfaces. The biggest reason that doctors hate EHRs is because of the forced complexity. EHRs, as currently implemented, lack the flexibility needed to make doctor's lives easier, and allow them to spend more time with their patients.
Currently, doctors have to fill out many fields which do not apply to every situation, and they must select and enter precise codes and descriptions.
An improved EHR would be organized into sections that can be skipped or selected as needed, and would allow more freeform entries, rather than codes. The reality is that medical records are shared between human professionals—not machines. Allow doctors to enter information in a freeform manner, and let them evolve best practices for describing the information.