VB6/MUMPS stack is... not ergonomic to code in.
Epic is easy to hate (it's everywhere), and for good reason. However, the alternatives are not obviously better unless there's been some radical innovation. There are definitely systems designed for a particular piece of a hospital (ex, ER, or labs, etc) that are probably better than Epic is, but when it comes to having one system for the entire hospital, they're all pretty bad.
The main problem is that the customer is not the nurses, it's the legal/financial/administrative side.