[nhamann]

I was able to find some sources. The first is this article: http://www.infoworld.com/d/developer-world/high-performance-....

> Easy-to-use computer systems, as we conventionally understand them, are not what Engelbart had in mind. You might be surprised to learn that he regards today’s one-size-fits-all GUI as a tragic outcome. That paradigm, he said in a talk at Accelerating Change 2004, has crippled our effort to augment human capability. High-performance tasks require high-performance user interfaces specially designed for those tasks. Instead of making every task lie on the Procrustean bed of the standard GUI, we should be inventing new, task-appropriate interfaces. No, they won’t work for everyone. Yes, they’ll require effort to learn. But in every domain there are some experts who will invest that effort in order to achieve greater mastery. We need to do more to empower those people.

The above cites Engelbart's 2004 talk "Large-Scale Collective IQ", so that is probably a good place to look as well.

There's also this page, which presents some interesting related comments by Alan Kay: http://traction.tractionsoftware.com/traction/permalink/Blog...

> Alan Kay: ... If you have ever seen anybody use NLS [Engelbart's 1968 hypertext system for which he invented the mouse and chord key set] it is really marvelous cause you're kindof flying along through the stuff several commands a second and there's a complete different sense of what it means to interact than you have today. I characterize what we have today as a wonderful bike with training wheels on that nobody knows they are on so nobody is trying to take them off. I just feel like we're way way behind where we could have been if it weren't for the way commercialization turned out.