Author of the posts here. There most definitely was a market, which ended only with the advent of cheaper computer-based solutions. Think magazines and small publications. The goal here was not to print a lot, but to produce a single instance of proportional, right-margin-justified, high-quality output that was ready for photocomposition. The output also definitely didn't look typewritten, but it looked as neat as what you would see in a magazine.
I remember encountering one of these machines in 1973 or 74 when I was on the high school newspaper staff. We visited another high school in our district that had one and I watched it output beautiful proportional, justified newspaper column-width text. I was amazed.
