What I wanted to do was a film documentary. What stopped me was, there was no footage! Meaning, nobody at CERL, the PLATO lab at U Illinois, had filmed everything. Nobody was a movie camera nerd. Nobody captured all the historical events, or even just day to day meetings / demos. It wasn't that kind of lab: everyone was insanely focused on the work at hand, and the culture was never one to expend any cycles on documenting how things went along the way. So there's a paper record, but very little in the way of footage. And if you do a documentary feature film you need TONS TONS TONS of video and film footage.
I did consider a website but ugh, it limits the audience. It doesn't get into bookstores. It doesn't get on college syllabi. You gotta do a book. So I did a book.
As for big financial loss, I knew going into the project I'd never make back what I put into the project over ~30 years. I didn't care; that wasn't the goal. The goal was to capture the story while the criticial mass of key PLATO people were still alive, and then put that into print so the world would know about PLATO before it all disappeared--believe me, the Silicon Valley tech industry would be perfectly happy if PLATO had disappeared. It messes so much with their mythology, after all! So that was a big motivator. The book has done fairly well, actually, and continues to sell in hardcover, paperback, and audiobook editions.