Remember, this was a low power computer with limited memory, for children, and getting it into the hands of those children as soon as possible was paramount. So, naturally, the user interface had to be alien and written completely from scratch in Python. Existing user interface paradigms were obviously a non-starter. Time-tested ways of doing things were not applicable. Children are not going to understand concepts such as background tasks and multiple windows. Have you ever seen a child try to use a real computer? They just don't get it. Everyone knows this.