You are absolutely correct about it being a hard market to crack.
My wife, who is a doctor, often complains that the various systems she has to deal with are often unusable.
When I was designing my new, general-purpose data management system that handles both structured and unstructured data well; she begged me to try to come up with a better system to manage medical data.
While I think my system has the potential to make a much better EMR; the work and money needed to break into that market felt beyond my reach.
A little startup with a superior architecture, but without all the political influence and domain knowledge to navigate the medical world; has little chance of gaining a foothold.