Epic takes actual feedback and development input from clinicians. They aren't just ignoring them. But it's not straightforward to make a system that handles all kinds of healthcare, integrates them together, avoids any bugs that could put a real human being at risk, and also appeases the clinicians, the regulators, the insurers, the lawyers, the administrators, and the capitalists.

With all those requirements, even the smallest feedback might require many hours to implement so things don't break or piss someone else off.