Why is it that people need to get a licence before we will trust them to obey the few simple rules of driving, and yet they are allowed to use a computer when they can't even type?
I think that both problems are of the same cloth. People demand that any work on computers be simpler than driving a car. People demand that using a web application must be simpler than using the same application on the desktop.
One possible reason is that web applications started out by being simpler/doing fewer things than desktop applications.
I think the solution is in not empasizing that something is a web application. It is simply an application that just happens to be accessed through the browser. If you don't follow that philosophy you can get caught in management's method of trying to make a complex problem simple by blindly converting it into a web application.