Solo was another of those pipedream products that pop up from time to time. For all the worthy bulls*** about having the machines made in Africa for local use, ExpLAN were expecting speculative investment in RISC OS by ROL or whoever without putting cash on the table to pay for it. That's never going to happen.
In addition, the double dose of evangelism, for an OS and a view of a god, would put most people off.
The other thing, forgotten by most people in the trade in its various forms, is that computers are almost totally useless. (