The screen-space-as-a-distraction argument sounds to me more like an excuse for not being able to keep one's attention on the task at hand. If a person can not resist filling the screen space up with useless clutter, it's that person's problem, not the problem of having the screen space. Someone else is able to use that extra screen space productively.
All in all it seems a "I can't have it, so I convinced myself that having it would be bad, so I don't miss it as much" self-deception.
Having (a) tried it various ways, and (b) having complete freedom as to how to organise my work life, I believe that keeping it small and simple and focussed works well on balance, at least for me. And it may work for others.
You do know that humans (other than yourself, maybe!) are not perfectly rational creatures? B^> Oscar Wilde's quote "I can resist anything except for temptation" is an astute observation.
It's not about being rational or not, it's about discipline (or perhaps about ADHD for some people). I can fall for many temptations, but when I want something done (either as a hobby, or at work), I have no problems concentrating on what I need to be doing. And having extra screen space often helps.
Depending on the task, of course - there are times when all I need is one 80x25 terminal, and then there are times when having several as large as possible windows open side by side helps a lot, e.g. when analyzing logs from several cluster nodes.
I love the Wilde quote, by the way, I don't think I've seen this one before. :)
