There is indeed support for structural editing, but we start the environment from the viewing use case. There are many ways to view data (or programs) and these

There is indeed support for structural editing, but we start the environment from the viewing use case. There are many ways to view data (or programs) and these are much less expensive and approachable than editing. For example, the distribution alone comes with thousands of object views. These then enable us to answer questions about the system without reading code (which happens to be the single largest expense in software engineering today).