In my experience (not the views of my employer) the most important stakeholder for an EHR is the ONC (federal government). Design-by-committee requirements with the happy coincidence of making it almost impossible to innovate or disrupt the industry. They change all the time, requiring a ton of dev effort just to stay in business, which favors giant companies who can afford that "rent". Next is health system administrators (whoever decides whether or not to buy, directly affecting revenue growth). Next is insurance companies. For the amount of revenue they pull in, a shocking amount of practices/hospitals/etc are so financially insecure that if the payers drag their feet for even a short period it can put them out of business. Actual healthcare providers and patients are too low on the list and it sucks.