I very much agree. I find it amazing that he does not get more credit. What is very unfortunate is that Ted never took the time to learn more about programming languages. For example file systems are there for a reason and only now, with all the computing power, can we partly realize alternative structures.
P.S.: TN is one of the most important thinkers of the 20th century. Perhaps not top10, but definitely top50, after Einstein, Freud, Chomsky, etc. He talked about personal computing before personal computers. He invented (i.e. thought of) Hypertext, before people did have access to computers. Building things is important, no doubt. But thinking about them is also important. Note the three thinkers I mentioned also never built anything. They wrote books/articles. For instance Nelson largely influenced IBM in building the PC. http://www.youtube.com/watch?v=Kasu0BhRFGo. He also influenced Steve Jobs, I believe quite heavily. At least Woz mentions the influence of Nelson and I think many ideas of Jobs actually came from Nelson in some sense.
In re hypertext, there is precedent in the widely published works of Vannevar Bush.
Nelson spent a lot of time refining many ideas that were not really viable before the availability of computers. Given the timeframe (growing up under the shadow of the Military Industrial Complex and then maturing during the Cold War/proxy wars) he hit a very ripe time for populist activists.
I do think Nelson is one of the most influential thinkers regarding information science, but not as much as he desperately reminds people that he was. I also do not think his limitation is his inability to program computers, as he had a number of well-funded people helping at different times.
I suspect that, if you were to sit down and force rank the 50 most important thinkers of the 20th century, you'd have to exclude Nelson. Had he realized his ideas in a timely fashion, or inspired anyone to realize and exceed his visions, then his place would be secured.
However, I think much of what he created, other than the specifics of a great potential implementation, would be classified as simultaneous invention. Semantic networks existed before hypertext and it's a pretty nominal step from there to the basics of hypermedia. The Mother of All Demos is probably the best example of his contemporaries realizing their ideas.
What he does have is charisma and an ability to communicate his ideas. He gets people fired up about his dreams of a better world, and yet it has not come to pass. No one has been inspired enough to implement Xanadu. It's appropriately named. It's an interrupted dream that is incomplete.
