In one of my first jobs we had the computer department that was separated from the rest of us by a glass wall. In those days their where a few reasons for this. The first was because the computers of the day produced so much heat so required special air conditioning to stop them melting themselves. As their where very few computer around at the time organisations wanted to show off there computer. However another main reason was because only the computer people where allowed to go near the computer, such that their was a lock on the door in the glass wall.
Later with the advent of desktop computers, these computers started to appear outside the glass wall. Now with personal computers notebook and net-book computers pads and phones the glass walls have disappeared and server rooms are mostly fully out of sight.
Even though the glass walls no longer exist the mentality of them still does and is becoming more prevalent.
Since the beginning of computing a programer had to write software to provide certain functionality to end uses. The programer and or the programing team would make decisions as to what end users could and could not do. In the early days because of the high cost and difficulty of developing software end users got very few options so where very much restricted in what they could do.
When the personal computers arrived with office productivity software and the like, end users had much greater flexibility in what they could do, even to the point of being able to modify the way they interfaced with operating system. However when users started to “mess up” there computers the computer people started to remove that flexibility, justifying the decisions with the argument that end users don't know what they are doing so they have to be protected from themselves.
I assert that this removing of flexibility for end users has swung the pendulum to far the other way such that now have a invisible glass computer wall so significantly reducing the flexibility that users have, not only computers, but also ever day used devices.